Session Fixation Affecting moodle/moodle package, versions >=3.0.0, <4.0.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PHP-MOODLEMOODLE-11335860
- published30 Jul 2025
- disclosed24 Jun 2025
- creditye_code
Introduced: 24 Jun 2025
CVE-2025-53021 (opens in a new tab)How to fix?
Upgrade moodle/moodle to version 4.0.0 or higher.
Overview
moodle/moodle is a learning platform.
Affected versions of this package are vulnerable to Session Fixation via the sesskey parameter. An attacker can gain unauthorized access to another user's session by obtaining and reusing the sesskey within the OAuth2 login flow, resulting in the victim's session being linked to the attacker's and potentially leading to full account takeover.
Notes:
- The issue was resolved as part of improvements to the OAuth flow login that were implemented in version 4.0.0
- Bug fixes for security issues in 3.11.x ended 11 December 2023, so a fix was not backported.