CVE catalog

CVE-2020-8517

squid: CVE-2020-8517

Severity: High · CVSS 8.1CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: Feb 3, 2020, 11:00:00 PM UTC
Source: [NVD] · [CVE record]
EPSS: 6.85% · Oct 25, 2026

An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with memory access protections, this can result in the helper process being terminated unexpectedly. This leads to the Squid process also terminating and a denial of service for all clients using the proxy.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	squid	sid	`7.7-1`	fixed
Debian	squid	forky	`7.7-1`	fixed
Debian	squid	trixie	`6.13-2+deb13u3`	fixed
Debian	squid	trixie-security	`6.13-2+deb13u2`	fixed
Debian	squid	bookworm	`5.7-2+deb12u5`	fixed
Debian	squid	bookworm-security	`5.7-2+deb12u6`	fixed
Alpine	squid	3.10	`4.10-r0`	fixed
Alpine	squid	3.11	`4.10-r0`	fixed
Alpine	squid	3.12	`4.10-r0`	fixed
Alpine	squid	3.13	`4.10-r0`	fixed
Alpine	squid	3.14	`4.10-r0`	fixed
Alpine	squid	3.15	`4.10-r0`	fixed
Alpine	squid	3.16	`4.10-r0`	fixed
Alpine	squid	3.17	`4.10-r0`	fixed
Alpine	squid	3.18	`4.10-r0`	fixed
Alpine	squid	3.19	`4.10-r0`	fixed
Alpine	squid	3.20	`4.10-r0`	fixed
Alpine	squid	3.21	`4.10-r0`	fixed
Alpine	squid	3.22	`4.10-r0`	fixed
Alpine	squid	3.23	`4.10-r0`	fixed
Alpine	squid	3.24	`4.10-r0`	fixed
Alpine	squid	3.8	`3.5.27-r4`	fixed
Alpine	squid	3.9	`4.10-r0`	fixed
Ubuntu	squid3	16.04	`3.3.8-1ubuntu16`	vulnerable
Ubuntu	squid3	16.04	`3.3.8-1ubuntu17`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu6`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.1`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.2`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.3`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.4`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.5`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.6`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.7`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.8`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.9`	vulnerable
Ubuntu	squid3	16.04	`3.5.12-1ubuntu7.10`	fixed
Ubuntu	squid3	18.04	`3.5.23-5ubuntu1`	vulnerable
Ubuntu	squid3	18.04	`3.5.23-5ubuntu2`	vulnerable
Ubuntu	squid3	18.04	`3.5.27-1ubuntu1`	vulnerable
Ubuntu	squid3	18.04	`3.5.27-1ubuntu1.1`	vulnerable
Ubuntu	squid3	18.04	`3.5.27-1ubuntu1.2`	vulnerable
Ubuntu	squid3	18.04	`3.5.27-1ubuntu1.3`	vulnerable
Ubuntu	squid3	18.04	`3.5.27-1ubuntu1.4`	vulnerable
Ubuntu	squid3	18.04	`3.5.27-1ubuntu1.5`	fixed
Ubuntu	squid	20.04	`4.8-1ubuntu2`	vulnerable
Ubuntu	squid	20.04	`4.8-1ubuntu3`	vulnerable
Ubuntu	squid	20.04	`4.9-2ubuntu1`	vulnerable
Ubuntu	squid	20.04	`4.9-2ubuntu2`	vulnerable
Ubuntu	squid	20.04	`4.9-2ubuntu3`	vulnerable
Ubuntu	squid	20.04	`4.9-2ubuntu4`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	squid	source	sid	`4.10-1`	unimportant	Not reported	Not reported
Debian	squid	source	forky	`4.10-1`	unimportant	Not reported	Not reported
Debian	squid	source	trixie	`4.10-1`	unimportant	Not reported	Not reported
Debian	squid	source	bookworm	`4.10-1`	unimportant	Not reported	Not reported
Alpine	squid	apk	3.10	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.11	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.12	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.13	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.14	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.15	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.16	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.17	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.18	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.19	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.20	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.21	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.22	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.23	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.24	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.8	`3.5.27-r4`	Not reported	ALPINE-CVE-2020-8517	Not reported
Alpine	squid	apk	3.9	`4.10-r0`	Not reported	ALPINE-CVE-2020-8517	Not reported
Ubuntu	squid3	deb	16.04	`3.5.12-1ubuntu7.10`	Not reported	UBUNTU-CVE-2020-8517	Not reported
Ubuntu	squid3	deb	18.04	`3.5.27-1ubuntu1.5`	Not reported	UBUNTU-CVE-2020-8517	Not reported
Ubuntu	squid	deb	20.04	`4.9-2ubuntu4`	Not reported	UBUNTU-CVE-2020-8517	Not reported

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

[squid]Unknown
Details (4)
- 5.7-2+deb12u5 · amd64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u5 · arm64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · amd64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · arm64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
[squid-cgi]Unknown
Source package: [squid]
Details (4)
- 5.7-2+deb12u5 · amd64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u5 · arm64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · amd64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · arm64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
[squidclient]Unknown
Source package: [squid]
Details (4)
- 5.7-2+deb12u5 · amd64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u5 · arm64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · amd64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · arm64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
[squid-common]Unknown
Source package: [squid]
Details (4)
- 5.7-2+deb12u5 · all · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u5 · all · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · all · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · all · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
[squid-openssl]Unknown
Source package: [squid]
Details (4)
- 5.7-2+deb12u5 · amd64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u5 · arm64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · amd64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · arm64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
[squid-purge]Unknown
Source package: [squid]
Details (4)
- 5.7-2+deb12u5 · amd64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u5 · arm64 · bookworm
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · amd64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12
- 5.7-2+deb12u6 · arm64 · bookworm-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · bookworm; dsa · squid · debian · 12

[Debian 13 (Trixie)]

[squid]Unknown
Details (4)
- 6.13-2+deb13u2 · amd64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · amd64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
[squid-cgi]Unknown
Source package: [squid]
Details (4)
- 6.13-2+deb13u2 · amd64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · amd64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
[squidclient]Unknown
Source package: [squid]
Details (4)
- 6.13-2+deb13u2 · amd64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · amd64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
[squid-common]Unknown
Source package: [squid]
Details (4)
- 6.13-2+deb13u2 · all · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · all · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · all · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · all · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
[squid-openssl]Unknown
Source package: [squid]
Details (4)
- 6.13-2+deb13u2 · amd64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · amd64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
[squid-purge]Unknown
Source package: [squid]
Details (4)
- 6.13-2+deb13u2 · amd64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · amd64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13
- 6.13-2+deb13u2 · arm64 · trixie-security
  Fixed · Fixed: 4.10-1
  dsa · squid · debian · 13

Observed: Oct 23, 2026, 5:53:32 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [SUSE security advisories and VEX]