Vulnerability CVE-2023-36459
Published: 2023-07-06

Description:
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.

Type:

CWE-79

 (Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'))

 References:
https://github.com/mastodon/mastodon/releases/tag/v3.5.9
https://github.com/mastodon/mastodon/security/advisories/GHSA-ccm4-vgcc-73hp
https://github.com/mastodon/mastodon/commit/6d8e0fae3e96f3cf4febe03fa7fcf5b95ff761b2
https://github.com/mastodon/mastodon/releases/tag/v4.0.5
https://github.com/mastodon/mastodon/releases/tag/v4.1.3
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