CVE-2025-53021

Description

A session fixation vulnerability in Moodle 3.x through 3.11.18 allows unauthenticated attackers to hijack user sessions via the sesskey parameter. The sesskey can be obtained without authentication and reused within the OAuth2 login flow, resulting in the victim's session being linked to the attacker's. Successful exploitation results in full account takeover. According to the Moodle Releases page, "Bug fixes for security issues in 3.11.x ended 11 December 2023." NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

Category

4.2
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.06%
Third-Party Advisory rentry.co
Affected: Moodle Moodle
Published at:
Updated at:

References

Link Tags
https://rentry.co/moodle-oauth2-cve third party advisory
https://github.com/moodle/moodle/releases/tag/v3.11.18 product
https://moodledev.io/general/releases#moodle-311 product

Frequently Asked Questions

What is the severity of CVE-2025-53021?
CVE-2025-53021 has been scored as a medium severity vulnerability.
How to fix CVE-2025-53021?
To fix CVE-2025-53021, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-53021 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-53021 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-53021?
CVE-2025-53021 affects Moodle Moodle.
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