CVE-2021-36395: Moodle - Denial of Service Vulnerability
Summary
CVE-2021-36395: In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service. Affects moodle across 3 version ranges.
< 3.9.8
>= 3.10.0, < 3.10.5
>= 3.11.0, < 3.11.1
Fixed in 3.9.8, 3.10.5 or 3.11.1, depending on the release line you run. How to fix ↓
Also tracked for
- moodle/moodle · Packagist
The same CVE-2021-36395 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
Moodle is an open-source learning management system used by educational institutions to create and manage online courses. It provides various features such as course management, user management, and content management. Moodle is widely used and has a large user base.
Vulnerability Detail
The vulnerability identified as CVE-2021-36395 in Moodle is related to the file repository's URL parsing. It lacks proper recursion handling, which can be exploited to launch a denial of service attack. An attacker can send a specially crafted URL that triggers excessive recursion, leading to resource exhaustion and potentially causing the Moodle instance to become unresponsive or crash. This vulnerability has a high severity rating and can have a significant impact on the availability of the Moodle platform.
How To Fix
Fixed versions by release line
The minimum fixed version depends on the release line you run.
-
< 3.9.83.9.8 -
>= 3.10.0, < 3.10.53.10.5 -
>= 3.11.0, < 3.11.13.11.1
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Workaround
There is no known workaround for this vulnerability. It is essential to apply the provided updates to address the issue effectively.
Conclusion
The vulnerability in Moodle's file repository URL parsing can be exploited to launch denial of service attacks. It is crucial for administrators to update their Moodle installations to the recommended versions to address this vulnerability and ensure the stability and security of their platforms. For further assistance with vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for moodle →
FAQ
The vulnerability can lead to a denial of service, potentially causing the Moodle platform to become unresponsive or crash.
All Moodle installations using versions prior to 3.9.8, 3.10.5, or 3.11.1 are affected by this vulnerability.
No, authentication is not required. An attacker can exploit this vulnerability remotely without any authentication.
There are no known instances of this vulnerability being exploited in the wild at the time of this report.
No, updating Moodle to the recommended versions is the only effective way to mitigate this vulnerability.
References
Related vulnerabilities
Recent vulnerabilities recorded for moodle.
