CVE-2023-36459

Summary

Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 1.3 and prior to versions 3.5.9, 4.0.5, and 4.1.3, an attacker using carefully crafted oEmbed data can bypass the HTML sanitization performed by Mastodon and include arbitrary HTML in oEmbed preview cards. This introduces a vector for cross-site scripting (XSS) payloads that can be rendered in the user's browser when a preview card for a malicious link is clicked through. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.

Impact & exploitability

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://github.com/mastodon/mastodon/commit/6d8e0fae3e96f3cf4febe03fa7fcf5b95ff761b2 ↗

Additional information

• NVD record
• https://github.com/mastodon/mastodon/commit/6d8e0fae3e96f3cf4febe03fa7fcf5b95ff761b2Patch
• http://www.openwall.com/lists/oss-security/2023/07/06/5
• https://github.com/mastodon/mastodon/releases/tag/v3.5.9Advisory
• https://github.com/mastodon/mastodon/releases/tag/v4.0.5Advisory
• https://github.com/mastodon/mastodon/releases/tag/v4.1.3Advisory
• https://github.com/mastodon/mastodon/security/advisories/GHSA-ccm4-vgcc-73hpAdvisory