CVE-2021-35210

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).

How to fix CVE-2021-35210

To remediate CVE-2021-35210, upgrade the affected package to a fixed version below.

• —upgrade to 4.9.16 or later
• —upgrade to 4.9.16 or later

Is CVE-2021-35210 being exploited?

Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

• >= 4.5.0, < 4.9.16
• >= 4.5.0, < 4.9.16

CVSS scores

References (6)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-35210
• PATCHgithub.com/contao/contao
• WEBcontao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021.html
• WEBgithub.com/contao/contao/security/advisories/GHSA-h58v-c6rf-g9f7