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: 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!  

Found this useful? 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: Remote Code Execution (RCE) Attacks

Time to update your boots!

Bootstrap v4.3.1 and v3.4.1 are out and available to patch an XSS vulnerability, CVE-2019-8331. For any users of the legacy 3.3.7, this will fix also other three XSS issues, namely CVE-2018-14040CVE-2018-14041 and CVE-2018-14042. Bootstrap now include a JavaScript sanitizer that will only allow whitelisted HTML elements in the data attribute of an element.

It’s available through all the channels: as NPM package, via CDNs and for old fashioned guys also as a direct download from Github. You do not have any excuses now, please upgrade!


Time to update your boots!

SAST, DAST, RASP, IAST explained

If you are working in application security you certainly heard one or more of these terms, but what’s the real meaning behind the acronym? In this article, I will try to clarify this tongue twister list.

SAST: Static Application Security Testing

This family groups all the technologies dedicate to test the security of code at rest and will try to detect possible security issues, based on some strategies or policies.

This category can be further divided into three others:

  • SCA – Static Code Analyzers
    They scan the code, in source or binary format, looking for patterns that can lead to security issues, they can also enforce guidelines and policies. There’s a lot of choice of tools in this area, but I think you should always include Error Prone, praised by Doug Lea.
  • SDA – Static Dependency Analyzers (also known as SCAN)
    They scan the external component pulled along your code build looking for known vulnerabilities that can potentially expose the code to exploits later. It’s worth mentioning here that on average 80% of the code you ship it’s not your code but is somebody else’s code! Meterian, our host here, is, in fact, a SAST/SDA tool.
  • SIS – Sensitive Information Scanners
    They scan the repositories where the code is stored in search of sensitive information inadvertently stored in them that can subsequently be leaked. It might sound a trivial thing to check, but it’s just good security hygiene to have one of such scanners in place. The effective to use greatly depend on your SDLC process, but I would strongly suggest using one of them, such as for example GitLeaks.

DAST: Dynamic Application Security Testing

This family groups tools used to test an application in an operating state (but not in production) using automated black box testing. They also frequently include specific security tests where the system tries to feed the application with malign data to simulate common patterns of attack. They interact with exposed interfaces such as APIs, network protocols, web pages. One opensource incarnation of such system is the Ebay DAST Proxy, released to the opensource community in late 2016.

RASP: Run-time Application Self-Protection

This is a very interesting category of tools where an agent is embedded into the application so that it protects the system at runtime and it’s typically deployed directly in production. The most common scenario sees the RASP agent “melted” with the application code through code instrumentation so that it can directly analyze the application behavior, providing active protection. A RASP, after detecting and blocking the attack, can shut down a user session, stop executing the application, and sometimes it also offers the ability to deploy code fixes at runtime. It also provides detailed reports that can be fed to monitoring systems. Baidu, the Chinese multinational technology company specializing in Internet-related services and product, is actively maintaining OpenRASP, an opensource RASP solution that works on Java and PHP web platforms.

IAST: Interactive Application Security Testing

These family of tools usually combine the RASP and DAST approaches: when testing an agent is embedded in the application while the test system executes attacks. This is a fully automated process so that it can be embedded in a continuous delivery system and ensure that a certain level of checking is done at frequently, even at every release, and with no human intervention.


What shall we do? As repeated endlessly again and again in the literature, you will need a complete approach to security testing, so considering using any of these tools is a step in the right direction. As we saw, there’re also opensource solutions available, so we do not really have any excuse to avoid putting this together.




SAST, DAST, RASP, IAST explained