CVE-2021-20187
CVE-2021-20187 is a high-severity vulnerability in Moodle with a CVSS 3.x base score of 7.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-829.
Key facts
- Severity: High (CVSS 3.x base score 7.2)
- CVSS v2: 6.5
- EPSS exploit prediction: 2% (72nd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-829
- Affected product: Moodle
- Published:
- Last modified:
Description
It was found in Moodle before version 3.10.1, 3.9.4, 3.8.7 and 3.5.16 that it was possible for site administrators to execute arbitrary PHP scripts via a PHP include used during Shibboleth authentication.
Frequently asked questions
- What is CVE-2021-20187?
- It was found in Moodle before version 3.10.1, 3.9.4, 3.8.7 and 3.5.16 that it was possible for site administrators to execute arbitrary PHP scripts via a PHP include used during Shibboleth authentication.
- How severe is CVE-2021-20187?
- CVE-2021-20187 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-20187 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-20187?
- CVE-2021-20187 primarily affects Moodle. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-20187?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-20187 published?
- CVE-2021-20187 was published on 2021-01-28 and last updated on 2026-06-17.
References
Affected products (2)
- cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*
- cpe:2.3:a:moodle:moodle:3.10.0:*:*:*:*:*:*:*
More vulnerabilities in Moodle
- CVE-2006-4935 — Critical (CVSS 10.0): The Database module in Moodle before 1.6.2 does not properly handle uploaded files, which has unspecified impact and…
- CVE-2006-4936 — Critical (CVSS 10.0): Moodle before 1.6.2 does not properly validate the module instance id when creating a course module object, which has…
- CVE-2005-2247 — Critical (CVSS 10.0): Multiple unknown vulnerabilities in Moodle before 1.5.1 have unknown impact and attack vectors.
- CVE-2004-2233 — Critical (CVSS 10.0): Unknown "front page vulnerability with Moodle servers" for Moodle before 1.3.2 has unknown impact and attack vectors.
- CVE-2004-2236 — Critical (CVSS 10.0): Unknown vulnerability in Moodle before 1.3.3 has unknown impact and attack vectors, related to language setting.
- CVE-2004-2237 — Critical (CVSS 10.0): Unknown vulnerability in Moodle before 1.3.4 has unknown impact and attack vectors, related to "strings in Moodle…
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