Squid before 4.13 and 5.x before 5.0.4 allows a trusted peer to perform Denial of Service by consuming all available CPU cycles during handling of a crafted Cache Digest response message. This only occurs when cache_peer is used with the cache digests feature. The problem exists because peerDigestHandleReply() livelocking in peer_digest.cc mishandles EOF.
http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_9.patch
https://github.com/squid-cache/squid/security/advisories/GHSA-vvj7-xjgq-g2jg
https://www.debian.org/security/2020/dsa-4751
https://usn.ubuntu.com/4477-1/
http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00012.html
http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00017.html
https://usn.ubuntu.com/4551-1/
https://lists.debian.org/debian-lts-announce/2020/10/msg00005.html
https://security.netapp.com/advisory/ntap-20210219-0007/
Source: MITRE
Published: 2020-08-24
Updated: 2021-07-21
Type: CWE-20
Base Score: 7.1
Vector: AV:N/AC:M/Au:N/C:N/I:N/A:C
Impact Score: 6.9
Exploitability Score: 8.6
Severity: HIGH
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Impact Score: 3.6
Exploitability Score: 3.9
Severity: HIGH