XSS in Discourse

CVE-2023-25172

Discourse is an open-source discussion platform. Prior to version 3.0.1 of the `stable` branch and version 3.1.0.beta2 of the `beta` and `tests-passed` branches, a maliciously crafted URL can be included in a user's full name field to to carry out cross-site scripting attacks on sites with a disabled or overly permissive CSP (Content Security Policy). Discourse's default CSP prevents this vulnerability. The vulnerability is patched in version 3.0.1 of the `stable` branch and version 3.1.0.beta2 of the `beta` and `tests-passed` branches. As a workaround, enable and/or restore your site's CSP to the default one provided with Discourse.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.005 (41.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N.

Affected products

  • Discourse — versions stable < 3.0.1, 3.1.0, tests-passed < 3.1.0.beta2

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-25172?
CVE-2023-25172 is a medium-severity vulnerability in Discourse, classified under Cross-site Scripting. CVSS score: 4.4/10. Published 2023-03-17.
How severe is CVE-2023-25172?
Medium severity. CVSS v3 base score is 4.4 out of 10.