Medium severity5.4NVD Advisory· Published May 16, 2023· Updated Jun 17, 2026

CVE-2021-27131

Description

Moodle 3.10.1 is vulnerable to persistent/stored cross-site scripting (XSS) due to the improper input sanitization on the "Additional HTML Section" via "Header and Footer" parameter in /admin/settings.php. This vulnerability is leading an attacker to steal admin and all user account cookies by storing the malicious XSS payload in Header and Footer. NOTE: this is disputed by the vendor because the "Additional HTML Section" for "Header and Footer" can only be supplied by an administrator, who is intentionally allowed to enter unsanitized input (e.g., site-specific JavaScript).

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected packages

Versions sourced from the GitHub Security Advisory.

Package	Affected versions	Patched versions
moodle/moodlePackagist	<= 3.10.1	—

Affected products

Moodle/Moodlecpe-rescue2 versions
(expand)+ 1 more
- (no CPE)
- cpe:2.3:a:moodle:moodle:3.10.1:*:*:*:*:*:*:*
osv-coords2 versions
pkg:bitnami/moodle pkg:composer/moodle/moodle
>= 3.10.1, < 3.10.2+ 1 more
- (no CPE)range: >= 3.10.1, < 3.10.2
- (no CPE)range: <= 3.10.1

Patches

Vulnerability mechanics

References

github.com/p4nk4jv/CVEs-Assigned/blob/master/Moodle-3.10.1-CVE-2021-27131.mdnvdExploitWEB
github.com/advisories/GHSA-w2pm-fr62-jgv4ghsaADVISORY
nvd.nist.gov/vuln/detail/CVE-2021-27131ghsaADVISORY
docs.moodle.org/402/en/RisksnvdWEB

News mentions

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cvss	0.351
epss	0.001
exploit	0.000
kev	0.000
patch	0.000
ransomware	0.000