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Vulnerability details: VCID-mkfz-e1ft-2bcw
Vulnerability ID VCID-mkfz-e1ft-2bcw
Aliases CVE-2021-20187
GHSA-2jrm-gww7-wch2
Summary Code Injection It was found in Moodle that it was possible for site administrators to execute arbitrary PHP scripts via a PHP include used during Shibboleth authentication.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (4)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-829 Inclusion of Functionality from Untrusted Control Sphere
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-94 Improper Control of Generation of Code ('Code Injection')
System Score Found at
epss 0.00679 https://api.first.org/data/v1/epss?cve=CVE-2021-20187
cvssv3.1 7.2 https://github.com/moodle/moodle
generic_textual HIGH https://github.com/moodle/moodle
cvssv3.1 7.2 https://moodle.org/mod/forum/discuss.php?d=417171
generic_textual HIGH https://moodle.org/mod/forum/discuss.php?d=417171
cvssv3.1 7.2 https://nvd.nist.gov/vuln/detail/CVE-2021-20187
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2021-20187
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-20187
https://github.com/moodle/moodle
https://moodle.org/mod/forum/discuss.php?d=417171
CVE-2021-20187 https://nvd.nist.gov/vuln/detail/CVE-2021-20187
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/moodle/moodle
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Found at https://moodle.org/mod/forum/discuss.php?d=417171
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-20187
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.7197
EPSS Score 0.00679
Published At June 4, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-06-04T16:20:46.056535+00:00 GitLab Importer Import https://gitlab.com/gitlab-org/advisories-community/-/blob/main/packagist/moodle/moodle/CVE-2021-20187.yml 38.6.0