Remote Code Execution due to Stored XSS in parisneo/lollms

Vulnerability Description

A vulnerability in the discussion image upload function of the Lollms application, version v9.9, allows for the uploading of SVG files. Due to incomplete filtering in the sanitize_svg function, this can lead to cross-site scripting (XSS) vulnerabilities, which in turn pose a risk of remote code execution. The sanitize_svg function only removes script elements and 'on*' event attributes, but does not account for other potential vectors for XSS within SVG files. This vulnerability can be exploited when authorized users access a malicious URL containing the crafted SVG file.

References

• https://huntr.com/bounties/ad68ecd6-44e2-449b-8e7e-f2b71b1b43c7
• https://github.com/parisneo/lollms/commit/328b960a0de2097e13654ac752253e9541521ddd