The Closest Encloser Proof aspect of the DNS protocol (in...

Vulnerability Description

The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance is skipped) allows remote attackers to cause a denial of service (CPU consumption for SHA-1 computations) via DNSSEC responses in a random subdomain attack, aka the "NSEC3" issue. The RFC 5155 specification implies that an algorithm must perform thousands of iterations of a hash function in certain situations.

References

• https://nlnetlabs.nl/news/2024/Feb/13/unbound-1.19.1-released/
• https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2024-01.html
• https://www.isc.org/blogs/2024-bind-security-release/
• https://datatracker.ietf.org/doc/html/rfc5155
• https://kb.isc.org/docs/cve-2023-50868
• https://gitlab.nic.cz/knot/knot-resolver/-/releases/v5.7.1
• https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2024q1/017430.html
• https://access.redhat.com/security/cve/CVE-2023-50868
• https://bugzilla.suse.com/show_bug.cgi?id=1219826
• http://www.openwall.com/lists/oss-security/2024/02/16/2
• http://www.openwall.com/lists/oss-security/2024/02/16/3
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SVYA42BLXUCIDLD35YIJPJSHDIADNYMP/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BUIP7T7Z4T3UHLXFWG6XIVDP4GYPD3AI/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PNNHZSZPG2E7NBMBNYPGHCFI4V4XRWNQ/
• https://lists.debian.org/debian-lts-announce/2024/02/msg00006.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TEXGOYGW7DBS3N2QSSQONZ4ENIRQEAPG/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UQESRWMJCF4JEYJEAKLRM6CT55GLJAB7/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RGS7JN6FZXUSTC2XKQHH27574XOULYYJ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HVRDSJVZKMCXKKPP6PNR62T7RWZ3YSDZ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6FV5O347JTX7P5OZA6NGO4MKTXRXMKOZ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IGSLGKUAQTW5JPPZCMF5YPEYALLRUZZ6/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZDZFMEKQTZ4L7RY46FCENWFB5MDT263R/
• https://security.netapp.com/advisory/ntap-20240307-0008/
• https://lists.debian.org/debian-lts-announce/2024/05/msg00011.html