Description

PyBB is an open source bulletin board. A manual code review of the PyBB bulletin board server has revealed that a vulnerability could have been exploited in which users could submit any type of HTML tag, and have said tag run. For example, a malicious `` that looks like ```xss``` could have been used to run code through JavaScript on the client side. The problem has been patched as of commit `5defd92`, and users are advised to upgrade. Attackers do need posting privilege in order to exploit this vulnerability. This vulnerability is present within the 0.1.0 release, and users are advised to upgrade to 0.1.1. Users unable to upgrade may be able to work around the attack by either; Removing the ability to create posts, removing the `|safe` tag from the Jinja2 template titled "post.html" in templates or by adding manual validation of links in the post creation section.

Classification

CVE ID: CVE-2023-34461

CVSS Base Severity: MEDIUM

CVSS Base Score: 4.6

Affected Products

Vendor: benjjvi

Product: PyBB

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.06% (probability of being exploited)

EPSS Percentile: 30.58% (scored less or equal to compared to others)

EPSS Date: 2025-02-03 (when was this score calculated)

References

https://github.com/benjjvi/PyBB/security/advisories/GHSA-mv96-w49p-438p
https://github.com/benjjvi/PyBB/commit/5defd922ab05a193a783392d447c6538628cf854

Timeline