{"id":"MGASA-2020-0315","summary":"Updated mumble packages fix security vulnerability","details":"Updated mumble package fixes security vulnerability:\n\n\nOCB2 is known to be broken under certain conditions:\nhttps://eprint.iacr.org/2019/311\n\nTo execute the universal attacks described in the paper, an attacker\nneeds access to an encryption oracle that allows it to perform encryption\nqueries with attacker-chosen nonce. Luckily in Mumble the encryption nonce\nis a fixed counter which is far too restrictive for the universal attacks\nto be feasible against Mumble.\n\nThe basic attacks do not require an attacker-chosen nonce and as such are\nmore applicable to Mumble. They are however of limited use and do require\nan en- and a decryption oracle which Mumble seemingly does not provide at\nthe same time.\n\nTo be on the safe side, this commit implements the counter-cryptanalysis\nmeasure described in the paper in section 9 for the sender and receiver side.\nThis way if either server of client are patched, their communication is almost\ncertainly (merely lacking formal proof) not susceptible to the attacks described\nin the paper.\n\n\nFixed: Potential exploit in the OCB2 encryption (#4227)\n","modified":"2026-04-16T04:25:46.900276Z","published":"2020-08-16T12:06:16Z","references":[{"type":"ADVISORY","url":"https://advisories.mageia.org/MGASA-2020-0315.html"},{"type":"REPORT","url":"https://bugs.mageia.org/show_bug.cgi?id=26746"},{"type":"REPORT","url":"https://github.com/mumble-voip/mumble/issues/4219"},{"type":"WEB","url":"https://github.com/mumble-voip/mumble/pull/4227"}],"affected":[{"package":{"name":"mumble","ecosystem":"Mageia:7","purl":"pkg:rpm/mageia/mumble?arch=source&distro=mageia-7"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.2-1.mga7"}]}],"ecosystem_specific":{"section":"core"},"database_specific":{"source":"https://advisories.mageia.org/MGASA-2020-0315.json"}}],"schema_version":"1.7.5","credits":[{"name":"Mageia","contact":["https://wiki.mageia.org/en/Packages_Security_Team"],"type":"COORDINATOR"}]}