CVE-2021-20183
Moodle Vulnerable to Reflected Cross-site Scripting
It was found in Moodle before version 3.10.1 that some search inputs were vulnerable to reflected XSS due to insufficient escaping of search queries.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
It was found in Moodle before version 3.10.1 that some search inputs were vulnerable to reflected XSS due to insufficient escaping of search queries.
- Record
CVE-2021-20183- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
It was found in Moodle before version 3.10.1 that some search inputs were vulnerable to reflected XSS due to insufficient escaping of search queries.
- Record
CVE-2021-20183- Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2022-5798 No score
It was found in Moodle before version 3.10.1 that some search inputs were vulnerable to reflected XSS due to insufficient escaping of search queries.
- Record
EUVD-2022-5798- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-xhfx-rm8q-c3xv
Moodle Vulnerable to Reflected Cross-site Scripting
It was found in Moodle before version 4.0.0-beta that some search inputs were vulnerable to reflected Cross-site Scripting (XSS) due to insufficient escaping of search queries.
- Record
GHSA-xhfx-rm8q-c3xv- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
It was found in Moodle before version 3.10.1 that some search inputs were vulnerable to reflected XSS due to insufficient escaping of search queries.
- Record
CVE-2021-20183- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-xhfx-rm8q-c3xv
Moodle Vulnerable to Reflected Cross-site Scripting
It was found in Moodle before version 4.0.0-beta that some search inputs were vulnerable to reflected Cross-site Scripting (XSS) due to insufficient escaping of search queries.
- Record
GHSA-xhfx-rm8q-c3xv- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-20183
It was found in Moodle before version 3.10.1 that some search inputs were vulnerable to reflected XSS due to insufficient escaping of search queries.
- Record
UBUNTU-CVE-2021-20183- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
OSVBIT-moodle-2021-20183 No score
It was found in Moodle before version 3.10.1 that some search inputs were vulnerable to reflected XSS due to insufficient escaping of search queries.
- Record
BIT-moodle-2021-20183- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
moodle/moodlePackagist |
3.10 up to 4.0.0-beta | 4.0.0-beta |
moodleBitnami |
before 3.10.1 | 3.10.1 |
moodle/moodlePackagist |
3.10 up to 4.0.0-beta, plus listed versions v3.10.0v3.10.0-betav3.10.0-rc1v3.10.0-rc2v3.10.1 Show 32 moreShow lessv3.10.10v3.10.11v3.10.2v3.10.3v3.10.4v3.10.5v3.10.6v3.10.7v3.10.8v3.10.9v3.11.0v3.11.0-betav3.11.0-rc1v3.11.0-rc2v3.11.1v3.11.10v3.11.11v3.11.12v3.11.13v3.11.14v3.11.15v3.11.16v3.11.17v3.11.18v3.11.2v3.11.3v3.11.4v3.11.5v3.11.6v3.11.7v3.11.8v3.11.9 |
4.0.0-beta |
moodleUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 2.7.9+dfsg-12.7.10+dfsg-12.7.11+dfsg-12.7.11+dfsg-22.7.12+dfsg-13.0.3+dfsg-0ubuntu13.0.3+dfsg-0ubuntu1+esm1 |
None known |
moodleUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 3.0.3+dfsg-0ubuntu13.0.3+dfsg-0ubuntu1+esm1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-20183 is a medium vulnerability (CVSS 5.4) in Moodle, published January 28, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.83%, the 57th percentile. Fixed in moodle/moodle 4.0.0-beta.