FreshRSS is a self-hosted RSS feed aggregator. Prior to version 1.26.2, its possible to poison feed favicons by adding a given URL as a feed with the proxy set to an attacker-controlled one and disabled SSL verifying. The favicon hash is computed by hashing the feed URL and the salt, whilst not including the following variables: proxy address, proxy protocol, and whether SSL should be verified. Therefore its possible to poison a favicon of a given feed by simply intercepting the response of the feed, and changing the website URL to one where a threat actor controls the feed favicon. Feed favicons can be replaced for all users by anyone. Version 1.26.2 fixes the issue.
The product, when processing trusted data, accepts any untrusted data that is also included with the trusted data, treating the untrusted data as if it were trusted.