CVE-2024-1931 – Denial of service when trimming EDE text on positive replies

https://notcve.org/view.php?id=CVE-2024-1931

NLnet Labs Unbound version 1.18.0 up to and including version 1.19.1 contain a vulnerability that can cause denial of service by a certain code path that can lead to an infinite loop. Unbound 1.18.0 introduced a feature that removes EDE records from responses with size higher than the client's advertised buffer size. Before removing all the EDE records however, it would try to see if trimming the extra text fields on those records would result in an acceptable size while still retaining the EDE codes. Due to an unchecked condition, the code that trims the text of the EDE records could loop indefinitely. This happens when Unbound would reply with attached EDE information on a positive reply and the client's buffer size is smaller than the needed space to include EDE records. • https://github.com/passer12/CVE-2024-1931-reproduction https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4VCBRQ7KMSIGBQ6A4SBL5PF326DIJIIV https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/B2JUIFPA7H75Q2W3VXW2TUNHK6NVGOX4 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RBR4H7RCVMJ6H76S4LLRSY5EBFTYWGXK https://lists.freebsd.org/archives/freebsd-security/2024-July/000283.html https://www.nlnetlabs.nl/downloads/unbound/CVE& • CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') •