Hi, Unbound 1.21.1 is available: https://nlnetlabs.nl/downloads/unbound/unbound-1.21.1.tar.gz sha256 3036d23c23622b36d3c87e943117bdec1ac8f819636eb978d806416b0fa9ea46 pgp https://nlnetlabs.nl/downloads/unbound/unbound-1.21.1.tar.gz.asc
** This release is signed by yor...@nlnetlabs.nl. Please find the relevant key at https://nlnetlabs.nl/people/ **
This security release fixes CVE-2024-8508. A vulnerability has been discovered in Unbound when handling replies with very large RRsets that Unbound needs to perform name compression for. Malicious upstreams responses with very large RRsets can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks. The vulnerability can be exploited by a malicious actor querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before Unbound replies to the query it will try to apply name compression which was an unbounded operation that could lock the CPU until the whole packet was complete. Unbound version 1.21.1 introduces a hard limit on the number of name compression calculations it is willing to do per packet. Packets that need more compression will result in semi-compressed packets or truncated packets, even on TCP for huge messages, to avoid locking the CPU for long. This change should not affect normal DNS traffic. We would like to thank Toshifumi Sakaguchi for discovering and responsibly disclosing the vulnerability. Bug Fixes: - Fix CVE-2024-8508, unbounded name compression could lead to denial of service. Best regards, -- Yorgos
