New Java Vulnerabilities!

4min read

Attention to all Java users! Yes, we are back with a brand new set of Java vulnerabilities that I know you would like to get some juicy info on. During September 2019, two Java vulnerabilities have been discovered within the Apereo CAS versions before 6.1.0-RC5 and the Apache Tapestry versions between 5.4.0 to 5.4.3. The former open source vulnerability has been given a score of 8.1 whilst the later a higher score of 9.8 in regards to severity. So hurry, read up and don’t waste any time. You could be affected!

  • CVE-2019-10754 Apereo CAS (org.apereo.cas:*) components could allow a remote authenticated malicious user to obtain sensitive information, caused by the use of weak RandomStringUtils PRNG algorithm. 
  • CVE-2019-0195 Manipulating classpath asset file URLs, an attacker could guess the path to a known file in the classpath and have it downloaded.


Vulnerability Score: 8.1 / HIGH

Platform: Java

Component: org.apereo.cas (Apereo CAS) 

Affected Versions: versions before 6.1.0-RC5

That’s right folks! Java has another vulnerability. Due to multiple classes using Apereo CAS (before the release of 6.1.0-RC5) and making use of apache commons-lang3 RandomStringUtils for token and ID generation, this has made them predictable and resulted in a cryptography weakness.

Apereo CAS is an open well-documented protocol, as well as an open-source Java server component. It provides support for multiple protocols (CAS, SAML, OAuth, OpenID) and is a library for clients such as Java, .NET, PHP, Perl, Apache, uPortal and more! Apereo’s mission is to help educational organizations ‘collaborate to foster, develop, and sustain open technologies and innovation to support learning, teaching and research’.

For example, org.apereo.cas:cas-server-support-simple-mfa is a package that allows Apereo CAS to act as a multifactor authentication provider by itself. This generates tokens and allows them to be sent to end-users via pre-defined communication channels such as email or text message. Please also note that this vulnerability affects multiple components of the Apereo CAS framework. 

So what is the threat? Well, the affected versions of this package are vulnerable to Insecure Randomness, as it relies on apache commons-lang3 RandomStringUtil  which can produce predictable results. So, this could allow an attacker to generate their own unique Ticket ID due to insufficient randomness. In other words, the attacker could guess the encryptionSecret used within GenerateJwtCommand and allow them to impersonate a user. This also means the attacker will have access to sensitive information caused by the use of the weak RandomStringUtils PRNG algorithm. 

Image showing user communicating with the server, and the hacker impersonating the user.

But don’t fret. There is a solution. It has been recommended to upgrade org.apereo.cas to version 6.1.0-RC5 or higher.

Java users, don’t give cyber criminals the chance to access your data. Act fast and upgrade org.apereo.cas! 


Vulnerability Score: 9.8 / CRITICAL

Platform: Java

Component: org.apache.tapestry (Apache Tapestry)

Affected Versions: versions 5.4.0 to 5.4.3.

We are not done yet folks! We have one more Java vulnerability to inform you guys on. Within the Apache Tapestry versions 5.4.0 to 5.4.3, the manipulating classpath asset file URLs allow an attacker to guess the path of a known file in the classpath and, as a result, download it. This was discovered on the 16/09/19 by Thiago H. de Paula Figueiredo.

The Apache Tapestry is an open-source framework for creating web applications in Java or other JVM languages. It also complements and builds upon standard Java Servlet API and works in any application server. Apache Tapestry has a long history. It has the oldest code, dating all the way back to 2000. This has resulted in many releases; developers now concentrate on Tapestry 5 as opposed to 3 and 4. 

What is tapestry.hmac-passphrase you say? This symbol is used to configure hash-based message authentication of Tapestry data stored in forms, or in the URL. In other words, your application is less secure and therefore more vulnerable to denial-of-service attacks. Especially when this symbol is not configured.

With various techniques, an attacker could guess the path to a known file in the classpath and have it downloaded. If the attacker found the file with the value of the  tapestry.hmac-passphrase configuration symbol, then they could use it to craft a Java deserialization attack, thus running a malicious injected Java code. 

Image showing a hacker guessing a file location, downloading the pass phrase and a computer showing it is has been hacked.

The recommended mitigation for this vulnerability has been suggested to upgrade to Tapestry 5.4.5, which is a drop-in replacement for any 5.4.x version. 

That is it from us…for now! Make sure to spread the word on these critically-rated Java vulnerabilities in order to help the app sec community defend against unwanted exploits. But as you all know, open-source vulnerabilities are discovered daily, so we recommend you regularly scan your code repositories for new known vulnerabilities. Don’t get caught off guard!

Knowing is half the battle. The other half is doing. Let Meterian help your dev team stay in the know and on top of the latest updates to secure your apps continuously.  Sign up here to download the Meterian client today.  You’ll get an instant analysis of your first project for free.  See the risks immediately and know which components to remove or upgrade to secure your app.

New Java Vulnerabilities!

How can your organization become more Cyber Resilient? 

Image of skyscrapers in the city with people on the top of each building. Represents the infrastructure of a company and the need to keep it cyber resilient.
Image from Free Vectors via

Cyber Resilience is demonstrating to be a very important concept within organizations’ strategies. Keeping up with the increasing investment in security is demanding investment in new technologies that can defend organizations faster. Meterian is one of them. But what really is Cyber Resilience? What does it entail? And why is it so important?

What is Cyber Resilience?

Cyber Resilience is the ability to prepare for, respond to, and recover from cyber attacks. It involves a strategic view, addressing the life cycle of data when it is created, dispersed and stored. More importantly, a cyber resilient approach will incorporate the collaboration of people, processes and technology. Careful not to confuse this concept with cyber security, which is the action of preventing an attack from happening. On the other hand, Cyber resilience is more about being persistent in your defensive strategies, to produce a preventive and reactive defense against threats and vulnerabilities.

Cyber attacks are only on the rise! According to Forbes Insights survey more than 50% of surveyed organizations have experienced at least one cyber incident in the last three years and only 27% believe that their top management understands the difference between mitigating cyber risk and working towards a more organised cyber resilient strategy. Normally, hacked victims have a better idea of how to prevent attacks as they have learnt from previous incidents. But this is no excuse for organizations to wait until the worst! Here are some steps which can boost your cyber resilience!

Identify, Protect, Detect, Respond, Recovery 

1. Identify

The first stage in adopting a cyber resilient strategy begins with the preparation and identification of the potential security risks within the framework of your organization. This involves spotting vital information and conducting assessments on vulnerabilities. Prioritising your most urgent issues will make you less appealing to attackers! Urgent issues might include securing your customers’ data such as financial credentials, passwords or emails.  Also, check how well do you understand the risks of each of the devices and digital assets identified in my company. 

What is sometimes overlooked, is the diversity needed within a team when understanding your organizations’ potential vulnerabilities. Accenture made a study which demonstrates how the immediate cybersecurity team only identified 64% of the breaches.  So involving groups beyond the cybersecurity team is vital to create a united front between IT and business. This will increase an organization’s resilience at all levels. Industry research supports this, highlighting how due to the variety of software services and devices used by users or staff, users must take responsibility to identify and act on risks. We need to make sure strong defence is across all user levels. After all, ‘Many Eyes Make All Bugs Shallow’

With identification, comes attention to detail. It is not enough to list ‘hacking’ as a risk, for this action could range from phishing to exploited databases. Without this attention to detail, organizations are vulnerable to more acute attacks. Checklists are useful practical tools to help identify the people, processes and technology within the organization needed to form an effective defense.  If you can identify these entities, then it’s easier to talk about the risks and do something about them. Review the NCSC Cloud Security Guidance which provides a framework of 14 cloud security principles for enterprises to evaluate the security of any cloud service.  The UK ICO provides a useful self-assessment checklist for SMEs to evaluate their data protection assurance. Discuss these lists with your teams to get visibility on what could be vulnerable to attacks and what the team can do to build an effective defense. 

2. Protect

Protection will help minimise chances of breaches succeeding. It will contain the impact of the attack. Develop safeguards for critical infrastructure and make sure to enforce regular checks to understand the strength of the organization’s cyber resilience. This will help keep good cyber hygiene within your organization.

People, process and technology are essential for this step. In particular, new technology solutions are important to protect infrastructure and assets. Continuously investing in upgrading and refining protective systems should become a normal cost of business. However, experts feel that these technologies are not being bought or implemented to the fullest extent. Maybe this is because cybersecurity technologies need to make business sense; they cannot work in isolation. Yet, there are many tools in place to help with the five NIST framework categories, meaning you don’t have to waste time with a platform that has things you don’t need. You can simply choose cyber security products customized to your business needs. 

Protection of the mobile workforce is also a crucial factor within cyber resilience. By controlling mobile access to the network, employees are restricted to sensitive corporate information. This ties in with monitoring and enforcing policy adherence, seeming as malicious insiders are one of the most frequent sources of cyber security breaches! There should also be regular staff training to avoid any human factors leading to an attack.

3.  Detect 

A rapid response to a cyber attack is crucial! The longer it takes the more cyber criminals can exploit your organization. For example, according to the 2019 Verizon Data Breach Investigations Report, the time of discovery tends to be months. Of course, it does depend on the type of attack in question. There is a difference between payment card compromises where discovery is based on the fraudulent use of the stolen data (taking weeks or months), and a stolen laptop. So be aware, slower detection will only make your systems more vulnerable. 

To avoid this time lag, there needs to be detection and response policies in place. These must be evaluated and updated frequently. New technologies and software are essential as we have to adapt to attackers becoming more advanced. Surprisingly, only 40% of companies are investing in areas such as AI, machine learning and automation to become more cyber resilient. Yet, we understand adopting new technology takes time. An organization will have to make sure new technology is implemented, setup and allocated accordingly to their employees. Then they can use it through training and the adoption of new policy definitions.

It might seem daunting, but if you find tools that are easy to use and set up, this will increase your organization’s agility to detect and mitigate risks faster.

4. Respond 

Create a response plan. This will help contain the impact of the attack once it has been detected. There should be a specific focus on: 

  • Who will be the single point of contact that takes on responsibility for the plan and for integrating incident-response efforts? This may be required across teams, business units and geographies, depending on the organization size and structure as well as the nature and consequence of the attack.
  • What will the incident response team look like? Which individuals are critical to involve and are there reasonable backup plans if an individual is unavailable?
  • How will relationships with key external stakeholders, such as law enforcement be maintained?
  • How will the organization work with external breach-remediation providers and experts?

These are all questions which should be coordinated amongst a Response Team, where roles should be assigned to competent members of your organization.

5. Recover 

Returning your organization back to normal after an attack can be tough. However, thinking ahead to these what-if incidents can make it easier to recover and get back to business as usual.  This is a good planning exercise for both organizations who have and haven’t suffered a cyber attack.

If your organization has suffered an attack: Was there anything missing that could have prevented the attack? What did you learn from the breach? What will you do differently next time? Or what is the organization in need of to resist a future attack? 

Having pre-defined strategies in place can help the recovery process.  For example, developing and implementing systems and plans to restore any lost data or disrupted services affected by the attack would help organizations recover systems as quickly as possible. This can be done through the use of backups, cloud storage and off-site archives. It is worrying that while most organizations perform regular backups, very few know exactly what it is they are backing up. Again, there is a need for prioritisation. What information being backed up is of most importance? And if a cyber attack occurs what information and services need to be restored first in order to return to normalcy? More importantly, this recovery plan needs to be re-evaluated and updated regularly. This will help meet any risk related aspects of an attack that an organization might encounter in the future. 

Image of work colleagues giving themselves a high five. Represents team work.
Image from

Put into Practice

Following these steps will help boost your cyber resilience. The combination of people, systems and technology collaborating together is vital to emphasize, as it shows a united IT and business front against cyber attacks. Yet, cyber resilience requires adaptability, so make sure complacency does not get in the way. 

  • Develop easily accessible quick-response guides for likely scenarios.
  • Establish processes for making major decisions, such as when to isolate compromised areas of the network.
  • Document response plans, update them regularly and make them available to the entire organization. 
  • Make sure all staff members understand their roles and responsibilities in the event of a cyber incident.
  • Train, practice, and run simulated breaches to develop response “muscle memory”, increase individuals’ awareness and fine-tune the organization’s response capabilities.

Be flexible, be proactive and cultivate cyber resilience.

How can your organization become more Cyber Resilient? 

Treasure your Ruby apps? Protect from unauthorised access immediately

5min read

Image of thief climbing out of laptop shining flashlight on Ruby icon, titled Vulnerability Focus: Ruby.

It’s that time of the week people. Meterian is back with information on a brand new set of vulnerabilities! We once again turn our heads to focus on two Ruby vulnerabilities. The first being found within the Ruby makandra consul gem, and the second being located within the Airbrake Ruby notifier 4.2.3. Both these open-source vulnerabilities are given a 9.8 severity score on NVD, so don’t waste any time –  read up, you could be affected!

  • CVE-2019-16377 The Ruby makandra consul gem for all versions prior to and including 1.0.2 has an Incorrect Access Control vulnerability. This can lead to unauthenticated access to certain controller actions.
  • CVE-2019-16060 The Airbrake Ruby notifier version 4.2.3 mishandles the blacklist_keys configuration option and may therefore may therefore disclose passwords to unauthorized actors.


Vulnerability Score: 9.8

Platform: Ruby

Component: consul gem

Affected Versions: <= 1.0.2

Yes, you heard right. A vulnerability has indeed been detected within the Ruby makandra consul gem for all versions prior to and including 1.0.2. It was discovered by Toby Craze (github id:kratob) on 23/09/19. We are afraid to be the bearer of bad news, but this serious security flaw will affect an unknown function of the component Access Control.

A little context: makandra has been working exclusively with Ruby on Rails since 2007. They are a team of Ruby developers and Linux system engineers based in Germany. Makandra are constantly using open-source software and security patches are applied to the systems they use on a weekly basis. During this time, it has successfully delivered more than 100 Rails projects on more than 90 servers, indicating the amount of users that are at risk of this security flaw. This security issue is located within the consul. For those who don’t know, the consul gem is an authorisation solution for Ruby on Rails and it uses scopes to control what a user can see or edit.

So what is the problem? When a controller has multiple power directives, the ‘:only’ and ‘:except’ of the last directive is applied to all directives. By sending a specially-crafted request, this can lead to an attacker gaining unauthorized access to certain controller actions. With the manipulation of an unknown input, comes a privilege escalation vulnerability. Unfortunately, the impact is negative on confidentiality, integrity and availability. Below is what the affected code would look like.

In this example of code, the powers ‘:foo’ and ‘:bar’ are only checked for the #index action. The other actions were left unprotected by powers checks.

The solution is simple. Upgrade to the latest version of the makandra consul gem (1.0.3. or later), which is available from the consul GIT Repository. or via rubygems. Act fast to get rid of this security bug from your codebases and apps! You could be affected!


Vulnerability Score: 9.8

Platform: Ruby

Component: airbrake-ruby gem

Affected Versions: 4.2.3

Attention Ruby users! The Airbrake Ruby notifier 4.2.3 has mishandled the blacklist_keys configuration option which could result in a very real threat of sensitive data being disclosed to unauthorized actors (e.g password or credentials dumping). What are blacklist_keys? This specifies which keys in the payload should be filtered. Before sending an error, filtered keys will be substituted with the [Filtered] label.

Image of computer, displaying a undisclosed User Name and Password credentials. They are being fished with by a hook. This symbolises the access to sensitive data.
Image from

Airbrake is a plain Ruby notifier gem that is used for integrating apps with Airbrake; it is the leading exception reporting service which provides minimalist API, enabling the notifier to send any Ruby exception to the Airbrake dashboard.  An exception is an event occurring during the execution of a program that disrupts the normal flow of the program’s instructions.  When an uncaught exception occurs, Airbrake could potentially release data to the Airbrake server.

The Airbrake dashboard provides easy categorization, searching, and prioritization of exceptions so that when errors occur, your team can quickly determine the root cause – this allows users to easily review errors, tie an error to an individual piece of code, and trace the cause back to recent changes.

So, what is the problem you say? A data-breach vulnerability–this is due to the mishandling of the blacklist_keys configuration option–within Airbrake Ruby 4.2.3 prevents user data from being filtered prior to sending to Airbrake. In other words, the vulnerability allows a remote attacker to access sensitive information on a targeted system. This compromised data could be user passwords or card payment details, which means an app could leak them  unknowingly; if left untreated, this could very well be the fatal zero-day vulnerability for a business or organization. 

To fix this vulnerability, users must upgrade to 4.2.4 or after. But hurry, as you might be at risk of attackers leaking important confidential data!

That is it for this round folks! Make sure to spread the word on these critically-rated Ruby vulnerabilities in order to help the app sec community defend against unwanted exploits. But as you all know, open-source vulnerabilities are discovered daily, so you can expect us to be back with new vulnerabilities very soon!

Knowing is half the battle. The other half is doing. Let Meterian help your dev team stay in the know and on top of the latest updates to secure your apps continuously. Sign up here to download the Meterian client today.  You’ll get an instant analysis of your first project for free.  See the risks immediately and know which components to remove or upgrade to secure your app.

Treasure your Ruby apps? Protect from unauthorised access immediately

Vulnerability Focus: PHP

5min read

Image of thief climbing out of laptop shining flashlight on PHP icon, titled Vulnerability Focus: PHP.

Listen up, app sec community – Meterian has an exciting update! We have a new addition to our family of languages for which our vulnerability scanning solution operates on. Drumroll please… it’s PHP. This means another layer of defense for your apps’ open-source dependencies to  shield them against malicious exploits. To commemorate this special day, we have written on 2 high-priority PHP vulnerabilities which will undoubtedly make an interesting read!

  • CVE-2019-9081 A vulnerability in the Illuminate component of Laravel Framework 5.7.x. could result in a remote cyber attack impacting confidentiality, integrity and availability in the process of web development.
  • CVE-2019-14933 A CSRF vulnerability in the Bagisto framework v0.1.5 could lead to attackers removing or manipulating important functionalities which will cause mass denial of services within an application.


Vulnerability Score: Critical––9.8 (CVSS v3.0)

Platform: PHP

Component: laravel/laravel

Affected versions: 5.7.0 – 5.7.27

Attention to all PHP programmers! Read up, this is important stuff. On the 24/02/19, a vulnerability was found in the Illuminate component of Laravel Framework 5.7.x., a PHP development framework based on PHP 7.1.3. The severity of the threat is understood when seeing that 107,933 live websites use Laravel. It is also said to be the most popular web app category in the United Kingdom. This demonstrates the scale of potentially affected users, and why action needs to be taken quickly to avoid security flaws. 

A graph depicting the rise in Laravel Usage Statistics. The statistics range from the years 2013-2019.
Laravel Usage Statistics:

The vulnerability is related to the __destruct method of the PendingCommand class in PendingCommand.php. It is a deserialization RCE (Remote Code Execution) vulnerability originating from a laravel core package and has shown to be triggered as long as the deserialized content is controllable. The access vector was through the network.

So what is the threat? In regards to CWE-502, when developers place restrictions on ‘gadget chains’ and method invocations that can self-execute during the deserialization process, this can allow attackers to leverage them to make unauthorized actions. For example, generating a shell. Manipulation with an unknown input leads to a privilege escalation vulnerability (code execution). Therefore, this vulnerability could have a negative impact on confidentiality, integrity and availability. Even worse, an attack can be initiated remotely with no form of authentication needed for exploitation. 

It is suggested to upgrade the laravel framework to version 5.7.27 or higher as soon as possible. So don’t waste any time! Or risk being vulnerable to potential cyber attacks!


Vulnerability Score: High — 8.8 (CVSS v3.0)

Platform: PHP

Component: bagisto

Affected versions: 0.1.5

Bagisto is a tailored e-commerce framework designed on some of the hottest open-source technologies such as Laravel, a PHP framework.  It cuts down on the resources needed to deploy an e-commerce platform (i.e. building online stores or migrating from physical stores). 

Alas, we regret to be the bearer of bad news. Version 0.1.5 of Bagisto has been found to contain a cross-site request forgery (CSRF) vulnerability which could result in client side manipulation that forces end users to execute unwarranted commands on a web application for which they are currently authenticated.  It should be noted that this compromised version allows for CSRF attacks under certain conditions, such as admin Uniform Resource Identifiers (URIs).  This CSRF vulnerability manipulates authenticated users’ browsers to send forged HTTP requests, including cookie sessions to exposed web applications. 

Here is some background information on the nature of CSRF attacks. Unlike remote code execution or command injection attacks, CSRF attacks specifically target state-changing requests as opposed to misappropriation of restricted data. Nonetheless, unauthorised state-changing requests can be equally bad; with the help of social engineering tactics (i.e. sending unwarranted links via email or chat support), attackers may trick end users into executing unsanctioned commands of the attackers’ choice. A successful CSRF attack could lead to vexing situations whereby attackers coerce end users into performing fund transfers, email address changes, and so forth. Furthermore, CSRF attacks can go as far as compromising entire web application systems upon gaining access to an administrator account.

In this context, hackers can trick end users by sending requests (i.e phishing emails) to lure them to open and display some apparently innocuous content in a new tab on the browser, which in turn, prompts it to execute the hidden malicious script, than can operate on behalf of the user.

This is a graphic illustrating the play-by-plat on how attackers can exploit the vulnerability to perform CSRF and remove important functionalities, which could lead to denial of services and loss of data on an e-commerce platform.
How attackers can exploit Bagisto open-source vulnerability

 The graphic above illustrates the play-by-play on how attackers can exploit this vulnerability to perform CSRF and remove important functionalities, which could lead to denial of services and loss of data on an e-commerce platform. 

In Step 1, the user first logs into the Bagisto admin page panel and subsequently  accesses a seemingly innocuous website on another tab in the user’s browser. This website contains a malignant script (placed by the hacker), and the action of accessing this tab will lead to Step 3 where the script will be executed; the browser is instructed by said script to perform any possible harmful action on behalf of the user in Step 3. This course of user action culminates in Step 4 with the server executing the requested malicious actions, such as deleting data on the admin panel.

Nonetheless, affected users will be glad to know that all versions of Bagisto following v0.1.5 are untouched by this CSRF vulnerability. So, there you have it – update your application to the latest version of the Bagisto framework at the soonest to avoid further exposure!

Spread the word on these vulnerabilities and their fixes to help us improve application security all-around. In any case, you can certainly expect more engaging reads on PHP in the near future. Until then!

Knowing is half the battle. The other half is doing. Let Meterian help your dev team stay in the know and on top of the latest updates to secure your apps continuously.  Sign up here to download the Meterian client today.  You’ll get an instant analysis of your first project for free.  See the risks immediately and know which components to remove or upgrade to secure your app.

Vulnerability Focus: PHP

Vulnerability Focus: Command Injection

5min read

Image of thief climbing out of laptop shining flashlight on ruby, java icons with a syringe, titled Vulnerability Focus: Command Injection

At attention, app sec community! It has been an exciting past couple of weeks, and we have got some juicy vulnerabilities to dish on. From Apache commons to the extensively-used Nokogiri library,  we will shed light on two compelling command injection vulnerabilities that rank highly on the common vulnerability scoring system (CVSS). Read along and spread the word to help combat against open source vulnerabilities.

  • CVE-2019-10086 The SuppressPropertiesBeanIntrospector class in versions before 1.9.4 of BeanUtils in Apache commons was not enabled by default

  • CVE-2019-5477 An inherent flaw in the Ruby Rexical gem v.1.0.6 or earlier, due to improper neutralization of special elements, resulted in a command injection vulnerability in the Nokogiri gem


Vulnerability Score: High — 7.3 (CVSS v3.0)

Platform: Java

Component: commons-beanutils

Affected versions: 1.9.3 and earlier

Take heed, all you Java programmers: a vulnerability has been located within Apache commons,  a provider of reusable open source Java component. There lies an arbitrary code vulnerability in the BeanUtils component, a set of utilities used for manipulation of JavaBeans code.

Within the BeanUtils component, there are several class types, or PropertyUtils beans, that  support mechanisms for dynamically defining and accessing bean properties (i.e. Bean Introspection) – these sets of utilities that assist in getting and setting property values on Java classes utilise the BeanIntrospector interface for components that can perform introspection on bean classes. 

Class TypeDescription
DefaultBeanIntrospectorThe default BeanIntrospector implementation

An implementation which detects write methods for properties used in fluent API scenario
SuppressPropertiesBeanIntrospector**A specialized BeanIntrospector implementation which suppresses some properties.

Example of class types and their functions
** highlights affected component in this CVE incident

In the context of this security flaw, the vulnerability originates from the SuppressPropertiesBeanIntrospector class type. This BeanIntrospector class type  is a standard implementation within a BeanUtils component which suppresses the ability for malicious attackers  to circumvent class properties of Java objects to gain access to the classloader. However, this safeguard mechanism against third-party exploitations of Java objects, was not enabled by default for version 1.9.2 – 1.9.3 of BeanUtils. 

This thereby allows attackers to manipulate classloaders and remotely execute arbitrary commands via class parameter, which would be detrimental to application security. Cyber attackers could potentially take advantage of this command injection loophole to inject malignant code into an application system through cross-site scripting (XSS), cross-site request forgery (XSRF), or drive-by attacks – this would then result in security breaches and a whole slew of inconvenience for organizations using  compromised versions of this BeanUtils component.

Affected users would be relieved to know that the fix for this vulnerability, version 1.9.4 of BeanUtils, has since been published. The security patch for apache-commons-beanutils has fixed the security flaw by adding a special BeanIntrospector class; this class type comprehensively suppresses the ability for any third party to access the classloader through the outmanoeuvring of class properties available on all Java objects – we can declare with utmost confidence that the updated BeanUtils bean prohibits all class level property access by default.

At the risk of sounding like a broken record, application systems that are using versions before 1.9.4 of the BeanUtils component ought to migrate to the latest version at the soonest. Don’t say you haven’t been warned!


Vulnerability Score: Critical — 9.8 (CVSS v3.0)

Platform: Ruby

Components: Rexical, Nokogiri

Affected versions: Rexical: 1.0.6 and earlier, Nokogiri: 1.10.3 and earlier

Mayday. I repeat, Mayday. Ruby users – watch out! A critical open-source security flaw has been located in Nokogiri, an open-source software library used to parse HTML and XML in Ruby. To provide some contextual information about its popularity, Nokogiri is indisputably one of the most downloaded Ruby gems – it has been downloaded over 240 million times from the This translates into a potentially vast network of compromised users – it would be prudent for affected parties to understand the type of security flaw they are dealing with.

In versions Nokogiri 1.10.3 or earlier, a command injection vulnerability allows attackers to alter dynamically generated content on a web page by inserting HTML code into input mechanisms that lack effective validation constraints. These commands are then executed in a subprocess via the kernel#open method, which renders an application vulnerable to remote code execution due to improper neutralization of special elements used in a command injection.

This is due to the core functionality of the kernel#open method. When instructed with a file path (defaulting with ‘r’) , it treats the script as the name of a file to open using the specified mode; but when the file path starts with a pipe character ‘I’, it interprets it as a shell command and returns an IO class linked to the subprocess.  In the context of this Nokogiri security flaw, these subprocesses are only exposed if the (undocumented) kernel#open method “Nokogiri::CSS:: Tokenizer#load_file” is executed with unvalidated user input in its filename.

This particular vulnerability exposure appears in the codework generated by Rexical gem versions 1.0.6 or earlier. The Rexical gem facilitates the Nokogiri library in generating a lexical scanner code that is used to parse CSS queries. In any case, the app sec community would be reassured to know that  a patch which addresses this key vulnerability has been released as Rexical v1.0.7. And on an equally heartening note, Nokogiri has also performed an upgrade (i.e. Nokogiri v.1.10.4) to implement the latest patch for the Rexical gem in their library.

Now that you are all caught up on these CVEs, we hope this little piece of enlightenment would have made you more aware of the rampantness of open source vulnerabilities!

Knowing is half the battle. The other half is doing. Let Meterian help your dev team stay in the know and on top of the latest updates to secure your apps continuously.  Sign up here to download the Meterian client today.  You’ll get an instant analysis of your first project for free.  See the risks immediately and know which components to remove or upgrade to secure your app.

Vulnerability Focus: Command Injection

Vulnerability Focus: Remote Code Execution (RCE) Attacks

This week’s edition is all about remote code execution attacks. We have a cross-site scripting (XSS) vulnerability in the ever popular http-file-server which could lead to the execution of arbitrary JavaScript code in an unsuspecting victim’s browser.  On the other hand, we have a RubyGem exposure whose sheer magnitude led to the discovery of a potential cryptocurrency mining scheme. 

  • CVE-2019-15224 A code-execution backdoor in rest-client version 1.6.13 could lead to privilege escalation attacks
  • CVE-2019-5458 A cross-site scripting (XSS) vulnerability in all versions of http-file-server, a third-party Node.JS module


Vulnerability Score: TBD  (CVSS v3.0)

Platform: Ruby

Component: rest-client

Affected versions: v1.6.10 through v1.6.13

A malicious code-execution backdoor has just been located in version 1.6.13 of rest-client – a popular HTTP and REST (REpresentational State Transfer) client software package for Ruby. In essence, REST is an architectural style that standardizes modes of communication among different computer systems on the web. To delve a bit deeper, RESTful systems are stateless, and they separate concerns from client-side and server-side – the Ruby rest-client oversees requests sent to the server in order to retrieve or modify data stored on the server. 

In this compromised  version, the injected code within the gem would fetch malicious code from and send it to the attacker’s server to retrieve sensitive information from the client’s host machine. Kudos to Jussi Kuljonen for catching this vulnerability and promptly notifying the GitHub community on 19 August 2019.  Aside from that, he also pointed out that rest-client version 1.6.10 leading up to version 1.6.13, which have since been yanked, were also compromised. 

This is an image of how a hacker exploits the Ruby gem rest-client library with remote code execution, in a web application.
Remote Code Execution Exploit of Ruby Gem rest-client library

This is dangerous territory for users of said gem, as third-party attackers could exploit this vulnerability to perform remote code execution for personal gains. This could be in the form of privilege escalation attacks, whereby attackers could execute malicious code on the host’s server to access credentials of services used by a hosting site (i.e. database, payment service provider).

It should be noted this 1.6.13  version is considerably dated, as the latest rest-client version is 2.1.0.rc1. This raised suspicions among the DevOps community that this incident might have been a targeted attack.

This discovery then instigated a wider instigation which revealed that the same code was found in almost a dozen other gems: bitcoin_vanity, blockchain_wallet, omniauth_amazon, cron_parser, coin_base,  lita_coin, awesome-bot, doge-coin, and capistrano-colors. It has been established that the attacker(s) wanted to exploit the infected hosts to covertly mine cryptocurrency. 

In terms of scope of impact, the rest-client  version 1.6.13, which sparked the uncovering of this malicious plot, has had 1061 downloads. On the other hand, the total download count for all the compromised gems is a little over 3500. Regardless, the chaos ceases here as all affected gems have been removed by the RubyGems team – the compromised accounts of developers have also been locked for good measure.

As for the availability of a fix, version 1.6.14 (identical to the unaffected  v1.6.9) has been released to replace all compromised versions in the legacy 1.6.x series. To check your apps’ depencies, versions <= 1.6.9 or >= 1.6.14 are unaffected. If your version of the rest-client gems falls in between, you are advised to download the patch immediately. Don’t say you haven’t been warned!

CVE-2019-5457, CVE-2019-5458

Vulnerability Score: Medium — 5.4  (CVSS v3.0)

Platform: Node.JS 

Components: http-file-server, min-http-server

Affected versions: All versions

Look alive, all you http-file-server and min-http-server users! A cross-site scripting (XSS) vulnerability has been found in these third-party Node.JS modules. The HTTP File Server (HFS) is a web server used for the publishing and sharing of files. 

By definition, XSS is a type of cybersecurity vulnerability that enables attackers to inject client-side scripts into web pages viewed by unsuspecting users. Implications of XSS vary in range (i.e. petty nuisance to  critical security risk), depending on the nature of the data stored on the vulnerable site’s server and the strength of the security mitigation measures adopted by the site’s network.

In this instance, this cross-site scripting (XSS) vulnerability is the attack vector – it enables hackers with access to the server-file system to inject malicious Javascript-based scripts in the file name, so that these scripts will be automatically executed on the victim’s browser when files are listed. In technical jargon, this is known as improper neutralization of input during web page generation. The occurrence of this XSS vulnerability is due to the unsanitized  and invalid HTML input in the module filenames – it allows any injected and stored scripts within the server to be executed in the client’s browser.

The http-file-server has unfortunately been declared dead, and no known fixes have been made available to HFS users. The good news is that the project has been yanked to prevent further exploits such as hijacking of user sessions or phishing to steal user credentials. Credits to An Nguyen for disclosing these easily exploitable vulnerabilities to the DevSecOps community!

To end things, we will leave you with some helpful tips on cross-site scripting prevention methods. One should check that user input has been sanitized and that potentially executable characters have been properly encoded to avoid having them interpreted as executable code. It is also worth validating input as it stops users from adding special characters into webpage data entry fields by refusing the request – this mitigates the impact should an attacker discover such an XSS vulnerability.  We suggest you bookmark this useful resource: Cross Site Scripting Prevention Cheat Sheet, too!  

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Vulnerability Focus: Remote Code Execution (RCE) Attacks