CVE-2023-2142 Nunjucks autoescape bypass leads to cross site scripting
Attackers can bypass autoescape to inject cross-site scripting payloads via backslash characters in user-controlled parameters.
- 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-2023-2142?
CVE-2023-2142 is a medium-severity cross-site scripting vulnerability in Mozilla Nunjucks, published on 26 Nov 2024. 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
In Nunjucks versions prior to version 3.2.4, it was possible to bypass the restrictions which are provided by the autoescape functionality. If there are two user-controlled parameters on the same line used in the views, it was possible to inject cross site scripting payloads using the backslash \ character.
Weakness: CWE-79
Which versions are affected by CVE-2023-2142?
2 open source packages ship an affected version, including nunjucks. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
nunjucks npm | All versions | 3.2.4 |
nunjucks npm | All versions | 3.2.4 |
Products include Mozilla Nunjucks.
How do I fix CVE-2023-2142?
Upgrade nunjucks to 3.2.4 or later.
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-2023-2142 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-2142 exists.
Other vulnerabilities in Mozilla Nunjucks
Sources
Also known as DEBIAN-CVE-2023-2142, GHSA-x77j-w7wf-fjmw, UBUNTU-CVE-2023-2142.