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.

CVE-2019-10754 

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. 

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! 

CVE-2019-0195

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. 

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.