GHSA-x77j-w7wf-fjmw
Nunjucks autoescape bypass leads to cross site scripting
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
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.
#### Example
If the user-controlled parameters were used in the views similar to the following:
```
<script>
let testObject = { lang: '{{ lang }}', place: '{{ place }}' };
</script>
```
It is possible to inject XSS payload using the below parameters:
```
https://<application-url>/?lang=jp\&place=};alert(document.domain)//
```
### Patches
The issue was patched in version 3.2.4.
### References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1825980
References
External links from the advisory. They lead to third-party sites.
- https://github.com/mozilla/nunjucks/security/advisories/GHSA-x77j-w7wf-fjmw
- https://nvd.nist.gov/vuln/detail/CVE-2023-2142
- https://github.com/mozilla/nunjucks/pull/1437
- https://github.com/mozilla/nunjucks/commit/ec16d210e7e13f862eccdb0bc9af9f60ff6749d6
- https://bugzilla.mozilla.org/show_bug.cgi?id=1825980
- https://github.com/mozilla/nunjucks
- https://github.com/mozilla/nunjucks/releases/tag/v3.2.4