Mastodon vulnerable to Cross-site Scripting through oEmbed preview cards
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.3epss 1.2%
exploitation probability
1.2%top 34% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
Affected products
mastodon · mastodonReferences
https://github.com/mastodon/mastodon/commit/6d8e0fae3e96f3cf4febe03fa7fcf5b95ff761b2https://github.com/mastodon/mastodon/releases/tag/v3.5.9https://github.com/mastodon/mastodon/releases/tag/v4.0.5https://github.com/mastodon/mastodon/releases/tag/v4.1.3https://github.com/mastodon/mastodon/security/advisories/GHSA-ccm4-vgcc-73hphttp://www.openwall.com/lists/oss-security/2023/07/06/5