Mastodon has improper authorship check on audience extension for existing posts
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.2epss 0.5%
exploitation probability
0.5%top 58% of all CVEs
observed exploitation
nono source reports it
Mastodon is a self-hosted, federated microblogging platform. Starting in version 2.6.0 and prior to versions 4.1.18 and 4.2.10, by crafting specific activities, an attacker can extend the audience of a post they do not own to other Mastodon users on a target server, thus gaining access to the contents of a post not intended for them. Versions 4.1.18 and 4.2.10 contain a patch for this issue.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Affected products
mastodon · mastodonReferences
https://github.com/mastodon/mastodon/commit/a1c7aae28aecf06659c5b18cfa131b37cd1512a3https://github.com/mastodon/mastodon/commit/d4bf22b632ea8b1174375c4966a6768ab66393b6https://github.com/mastodon/mastodon/releases/tag/v4.1.18https://github.com/mastodon/mastodon/releases/tag/v4.2.10https://github.com/mastodon/mastodon/security/advisories/GHSA-xjvf-fm67-4qc3