CyberRota Analysis
AI-GeneratedCommunity moderators in Lemmy versions 0.19.18 to 0.19.19 and 1.0.0-alpha.20 can exploit a flaw that allows them to feature or unfeature posts from unrelated communities, undermining the integrity of content curation. This vulnerability could lead to unauthorized promotion or demotion of posts, impacting the visibility and reputation of affected communities. Organizations using these versions should prioritize updating to the fixed versions to mitigate the risk of community manipulation.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
Lemmy is a link aggregator and forum for the fediverse. From 0.19.18 until 0.19.19 and 1.0.0-alpha.20, a community moderator can feature or unfeature posts in other communities through federated CollectionAdd and CollectionRemove activities using CollectionType::Featured. After verify_mod_action authorizes the actor against self.community(), the receive handlers in crates/apub/activities/src/community/collection_add.rs and crates/apub/activities/src/community/collection_remove.rs dereference self.object as an ApubPost and update featured_community without verifying that post.community_id equals community.id. A moderator can therefore target an unrelated post owned by another community, push it into featured feeds and listings, or undo another community's legitimate curation decision. This issue is fixed in versions 0.19.19 and 1.0.0-alpha.20.