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mozilla/nunjucks · Security

Nunjucks autoescape bypass leads to cross site scripting

GHSA ID
GHSA-x77j-w7wf-fjmw
CVE ID
CVE-2023-2142
Severity
medium
Published
Updated
CVSS
6.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v3
6.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4
5.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

Description

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

CWEs

  • CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

References

Open GitHub