CVE-2020-24606

Name: CVE-2020-24606
Creator: NVD / NIST
Published: 2020-08-24T18:15:10.047+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 5.16%

Last modified Jun 17, 2026

CVE-2020-24606 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 5.16% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

5.16%

91.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-667

Affected Software

Vendor	Product	Versions
Squid-Cache	Squid	>= 3.0, < 4.13
Squid-Cache	Squid	>= 5.0.1, < 5.0.4
Canonical	Ubuntu Linux	16.04
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	20.04
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0
Fedoraproject	Fedora	31
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Opensuse	Leap	15.1
Opensuse	Leap	15.2

References

http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00012.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00017.htmlMailing List, Third Party Advisory
http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_9.patchPatch, Vendor Advisory
https://github.com/squid-cache/squid/security/advisories/GHSA-vvj7-xjgq-g2jgThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/10/msg00005.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BE6FKUN7IGTIR2MEEMWYDT7N5EJJLZI2/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BMTFLVB7GLRF2CKGFPZ4G4R5DIIPHWI3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HJJDI7JQFGQLVNCKMVY64LAFMKERAOK7/
https://security.netapp.com/advisory/ntap-20210219-0007/Third Party Advisory
https://security.netapp.com/advisory/ntap-20210226-0006/Third Party Advisory
https://security.netapp.com/advisory/ntap-20210226-0007/Broken Link
https://usn.ubuntu.com/4477-1/Third Party Advisory
https://usn.ubuntu.com/4551-1/Third Party Advisory
https://www.debian.org/security/2020/dsa-4751Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00012.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00017.htmlMailing List, Third Party Advisory
http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_9.patchPatch, Vendor Advisory
https://github.com/squid-cache/squid/security/advisories/GHSA-vvj7-xjgq-g2jgThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/10/msg00005.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BE6FKUN7IGTIR2MEEMWYDT7N5EJJLZI2/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BMTFLVB7GLRF2CKGFPZ4G4R5DIIPHWI3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HJJDI7JQFGQLVNCKMVY64LAFMKERAOK7/
https://security.netapp.com/advisory/ntap-20210219-0007/Third Party Advisory
https://security.netapp.com/advisory/ntap-20210226-0006/Third Party Advisory
https://security.netapp.com/advisory/ntap-20210226-0007/Broken Link
https://usn.ubuntu.com/4477-1/Third Party Advisory
https://usn.ubuntu.com/4551-1/Third Party Advisory
https://www.debian.org/security/2020/dsa-4751Third Party Advisory

Timeline

Published: Aug 24, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-24606?

How severe is CVE-2020-24606?

CVE-2020-24606 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 5.16% probability of exploitation in the next 30 days.

How do I fix CVE-2020-24606?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-24606?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST