CVE-2021-35210 Cross site scripting in the system log
Attackers can inject malicious scripts into the system log, leading to code execution in the browser when viewed in the back end.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-35210?
CVE-2021-35210 is a medium-severity cross-site scripting vulnerability in n/a, published on 23 Jun 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Contao 4.5.x through 4.9.x before 4.9.16, and 4.10.x through 4.11.x before 4.11.5, allows XSS. 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.
Weakness: CWE-79
Which versions are affected by CVE-2021-35210?
8 open source packages ship an affected version, including contao/contao and contao/core-bundle. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
contao/contao Packagist | From 4.10.0 | 4.11.5 |
contao/contao Packagist | From 4.10.0 | 4.11.5 |
contao/contao Packagist | From 4.5.0 | 4.9.16 |
contao/contao Packagist | From 4.5.0 | 4.9.16 |
contao/core-bundle Packagist | From 4.10.0 | 4.11.5 |
contao/core-bundle Packagist | From 4.10.0 | 4.11.5 |
2 more packages
contao/core-bundle Packagist | From 4.5.0 | 4.9.16 |
contao/core-bundle Packagist | From 4.5.0 | 4.9.16 |
Products include Contao Contao.
How do I fix CVE-2021-35210?
Upgrade contao/contao to a fixed version for your release line: 4.11.5 or 4.9.16.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2021-35210 being exploited?
There is no known exploitation of CVE-2021-35210 in the wild and no public exploit code.
Other vulnerabilities in n/a
- CVE-2022-26265 Remote Code Execution in Contao Managed Edition
- CVE-2019-11512 Contao SQL injection in the file manager
- CVE-2012-4383 Contao core SQL Injection Vulnerability
- CVE-2019-19745 Unrestricted file uploads in Contao
- CVE-2024-28235 Contao possible cookie sharing with external domains while checking protected pages for broken links
Sources
Also known as GHSA-h58v-c6rf-g9f7.