CVE-2021-35210
MEDIUM6.1EPSS 0.37%Cross site scripting in the system log
Published: 7/1/2021Modified: 3/13/2026
Description
### Impact It is possible to inject code into the `tl_log` table that will be executed in the browser when the system log is called in the back end. ### Patches Update to Contao 4.9.16 or 4.11.5. ### Workarounds Disable the system log module in the back end for all users (especially admin users). ### References https://contao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021 ### For more information If you have any questions or comments about this advisory, open an issue in [contao/contao](https://github.com/contao/contao/issues/new/choose).
Affected packages (2)
- Packagist/contao/contao>= 4.5.0, < 4.9.16
- Packagist/contao/core-bundle>= 4.5.0, < 4.9.16
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2021-35210
- PATCHhttps://github.com/contao/contao
- WEBhttps://contao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021.html
- WEBhttps://github.com/contao/contao/security/advisories/GHSA-h58v-c6rf-g9f7
- WEBhttps://github.com/FriendsOfPHP/security-advisories/blob/master/contao/contao/CVE-2021-35210.yaml
- WEBhttps://github.com/FriendsOfPHP/security-advisories/blob/master/contao/core-bundle/CVE-2021-35210.yaml