CVE-2017-9841: Drupal Sites Exploited Using PHPUnit Vulnerability in Mailchimp Modules (PSA-2019-0904)
Attackers are leveraging a vulnerability patched nearly three years ago to target Drupal sites.
Background
On September 4, Drupal published PSA-2019-09-04, a public service announcement (PSA) for a vulnerability in a third-party library in a Drupal module that’s being actively exploited in the wild.
Analisi
CVE-2017-9841 is a code injection vulnerability in PHPUnit, a PHP unit testing framework. The PHPUnit library is part of the Mailchimp and Mailchimp E-Commerce modules in Drupal which, according to their modules pages, are currently used by over 25,000 sites combined.
In June 2017, a Twitter account called “vulnbusters” was created and published an advisory for the vulnerability on their now-defunct website, which is available through the Internet Archive’s Wayback Machine here.
The advisory identifies the vulnerability within the /phpunit/src/Util/PHP/eval-stdin.php file through its use of the php://input wrapper. Patched versions of PHPUnit use the php://stdin wrapper instead. An unauthenticated attacker could exploit this vulnerability by sending an HTTP POST request to a web server containing the vulnerable eval-stdin.php file, leading to arbitrary code execution.
Previous versions of PHPUnit contained the code injection vulnerability which, according to the Vulnbusters advisory page, was unknowingly patched in November 2016 in PHPUnit version 4.8.28 and version 5.6.3 to address issues with insulated tests using phpdbg.
In February 2018, an issue was filed on the Mailchimp project on Drupal from a user who was contacted by their hosting provider, indicating that the eval-stdin.php on their web server was malicious. A different user, who commented on the same issue in May 2018, also received the same feedback from their hosting provider. Separately, in February 2018, Kevin Beaumont (@GossiTheDog) found attackers were targeting a Drupal honeypot attempting to exploit CVE-2017-9841.
Ok, MailChimp API ships PHPunit, which as a remote unauthenticated code execution bug https://t.co/fAQjErb2ed - there’s no known exploit I can see but somebody has one.
— Kevin Beaumont (@GossiTheDog) February 26, 2018
Outside of Drupal, CVE-2017-9841 has also been found in WordPress plugins, such as the Jekyll Exporter plugin, as well as MediaWiki and open source learning platform Moodle.
Proof of concept
A proof-of-concept (PoC) was originally published in the Vulnbusters advisory from June 2017.
Solution
As previously mentioned, CVE-2017-9841 was patched in PHPUnit back in November 2016. The vulnerability affected specific versions of PHPUnit, which are referenced in the table below.
| Vulnerable PHPUnit Versions | Fixed PHPUnit Versions |
|---|---|
| 4.8.19 - 4.8.27 | 4.8.28 or later |
| 5.0.10 - 5.6.2 | 5.6.3 or later |
For the Mailchimp and Mailchimp E-Commerce modules, version 1.0.7 or below for the Mailchimp API for PHP is considered vulnerable. The Drupal Security team notes even if Drupal customers had previously installed these modules, there may still be artifacts left over from the installation on the web server. Vulnerable servers may have the eval-stdin.php. If the file exists and it references the php://input wrapper instead of the php://stdin wrapper, then the server is vulnerable to CVE-2017-9841.
Identifying affected systems
A list of Tenable plugins to identify this vulnerability will appear here as they’re released.
Get more information
- Drupal Advisory for CVE-2017-9841
- Tenable CVE Summary: CVE-2017-9841
- Archive.org Entry for Vulnbusters
Join Tenable's Security Response Team on the Tenable Community.
Learn more about Tenable, the first Cyber Exposure platform for holistic management of your modern attack surface.
Get a free 60-day trial of Tenable.io Vulnerability Management.
Articoli correlati
Cybersecurity Snapshot: Guide Unpacks Event-Logging Best Practices, as FAA Proposes Stronger Cyber Rules for Airplanes
August 23, 2024Looking to sharpen your team’s event logging and threat detection? A new guide offers plenty of best practices. Plus, the FAA wants airplanes to be more resilient to cyberattacks. Meanwhile, check out the critical vulnerabilities Tenable discovered in two Microsoft AI products. And get the latest on ransomware trends, vulnerability management practices and election security!
Detecting Risky Third-party Drivers on Windows Assets
August 7, 2024Kernel-mode drivers are critical yet risky components of the Windows operating system. Learn about their functionality, the dangers they pose, and how Tenable's new plugins can help identify and mitigate vulnerabilities using community-driven resources like LOLDrivers.
Never Trust User Inputs -- And AI Isn't an Exception: A Security-First Approach
August 6, 2024As AI transforms industries, security remains critical. Discover the importance of a security-first approach in AI development, the risks of open-source tools, and how Tenable's solutions can help protect your systems.
Cybersecurity Snapshot: Guide Unpacks Event-Logging Best Practices, as FAA Proposes Stronger Cyber Rules for Airplanes
August 23, 2024Looking to sharpen your team’s event logging and threat detection? A new guide offers plenty of best practices. Plus, the FAA wants airplanes to be more resilient to cyberattacks. Meanwhile, check out the critical vulnerabilities Tenable discovered in two Microsoft AI products. And get the latest on ransomware trends, vulnerability management practices and election security!
SSRFing the Web with the Help of Copilot Studio
August 20, 2024Tenable Research discovered a critical information-disclosure vulnerability in Microsoft’s Copilot Studio via a server-side request forgery (SSRF), which allowed researchers access to potentially sensitive information regarding service internals with potential cross-tenant impact.
Cybersecurity Snapshot: First Quantum-resistant Algorithms Ready for Use, While New AI Risks’ Database Is Unveiled
August 16, 2024NIST has released the first encryption algorithms that can protect data against quantum attacks. Plus, MIT launched a new database of AI risks. Meanwhile, the CSA published a paper outlining the unique risks involved in building systems that use LLMs. And get the latest on Q2’s most prevalent malware, the Radar/Dispossessor ransomware gang and CVE severity assessments!
- Threat Intelligence
- Threat Management
- Vulnerability Management
- Vulnerability Scanning