Description
An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if the pooled token credentials are freed (instead of replayed as valid credentials).
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | squid | 4.11-1 | — |
| Debian 13 | squid | 4.11-1 | — |
| Debian 12 | squid | 4.11-1 | — |
| Debian 10 | squid | 4.6-1+deb10u2 | DSA-4682-1 |
| Debian 9 | squid3 | 3.5.23-5+deb9u2 | DLA-2278-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | squid | 4.10-1ubuntu1.1 | USN-4356-1 |
| Ubuntu 18.04 LTS | squid3 | 3.5.27-1ubuntu1.6 | USN-4356-1 |
| Ubuntu 16.04 LTS | squid3 | 3.5.12-1ubuntu7.11 | USN-4356-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2020:2041 |
| RHEL 8 | squid | 7:4.4-8.module+el8.2.0+6449+6ba3df3e.1 | RHSA-2020:2041 |
| RHEL 7 | squid +2 | 7:3.5.20-15.el7_8.1 | RHSA-2020:2040 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.1 EUS | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2020:2039 |
| RHEL 8.1 EUS | squid | 7:4.4-8.module+el8.1.0+6436+af881f9b.1 | RHSA-2020:2039 |
| RHEL 8.0 E4S | libecap +1 | 1.0.1-2.module+el8.0.0+4045+70edde92 | RHSA-2020:2038 |
| RHEL 8.0 E4S | squid | 7:4.4-5.module+el8.0.0+6430+d78e5241.1 | RHSA-2020:2038 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | libecap +1 | 1.0.1-2.module_el8.6.0+2741+01592ae8 | ALSA-2020:2041 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | libecap | 1.0.1-2.module+el8.4.0+404+316a0dc5 | RLSA-2020:2041 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | squid | 4.11-5.17.2 | SUSE-SU-2020:1156-1 |
| SLES 15 | squid | 4.11-5.17.2 | SUSE-SU-2020:1156-1 |
| SLES 12 SP5 | squid | 4.11-4.9.1 | SUSE-SU-2020:1134-1 |
| SLES 12 SP4 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
| SLES 12 SP3 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
| SLES 11 SP4 | squid3 | 3.1.23-8.16.37.12.1 | SUSE-SU-2020:14460-1 |
| SLES for SAP 15 | squid | 4.11-5.17.2 | SUSE-SU-2020:1156-1 |
| SLES for SAP 12 SP5 | squid | 4.11-4.9.1 | SUSE-SU-2020:1134-1 |
| SLES for SAP 12 SP4 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
| SLES for SAP 12 SP3 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
| SLES for SAP 12 SP2 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
| SLE HPC 15 | squid | 4.11-5.17.2 | SUSE-SU-2020:1156-1 |
| SUSE OpenStack Cloud Crowbar 8 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
| SUSE OpenStack Cloud 8 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
| SUSE OpenStack Cloud 7 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | squid3 | 3.1.23-8.16.37.12.1 | SUSE-SU-2020:14460-1 |
| SUSE HPE Helion OpenStack 8 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
| SUSE Enterprise Storage 5 | squid | 3.5.21-26.23.1 | SUSE-SU-2020:1227-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | squid | 4.16-1.5 | openSUSE-SU-2024:11403-1 |
| openSUSE Leap 15.1 | squid | 4.11-lp151.2.15.2 | openSUSE-SU-2020:0623-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.11 | squid | 4.11-r0 | — |
| Alpine v3.10 | squid | 4.11-r0 | — |
| Alpine v3.9 | squid | 4.11-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | squid +2 | 7:3.5.20-15.amzn2.1 | ALAS2-2020-1448 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | libecap +1 | 1.0.1-2.module+el8.1.0+5405+03b963f4 | ELSA-2020-2041 |
| Oracle Linux 8 | squid | 7:4.4-8.module+el8.2.0+7611+d512f060.1 | ELSA-2020-2041 |
| Oracle Linux 7 | squid +2 | 7:3.5.20-15.el7_8.1 | ELSA-2020-2040 |
Advisories 19
- RHSA-2020:2038 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- ALSA-2020:2041 Important: squid:4 security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2020:2040 Red Hat Security Advisory: squid security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-4682-1 squid - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2278-1 squid3 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-4356-1 squid, squid3 vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- RLSA-2020:2041 Important: squid:4 security update Rocky Linux Security Advisories · Feb 5, 2026
- SUSE-SU-2020:1227-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1134-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11403-1 squid-4.16-1.5 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0623-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1156-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2020:2041 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Jan 14, 2026
- RHSA-2020:2039 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- SUSE-SU-2020:14460-1 Security update for squid3 SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2023-2474 Squid: Schwachstelle ermöglicht Ausführen von beliebigem Programmcode BSI CERT-Bund (WID) · Sep 27, 2023
- ALAS2-2020-1448 Important: squid security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 1, 2020
- ELSA-2020-2041 Important: squid:4 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 12, 2020
- ELSA-2020-2040 Important: squid security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · May 7, 2020
References
- http://www.squid-cache.org/Versions/v4/changesets/squid-4-eeebf0f37a72a2de08348e85ae34b02c34e9a811.patch
- http://master.squid-cache.org/Versions/v4/changesets/squid-4-eeebf0f37a72a2de08348e85ae34b02c34e9a811.patch
- https://github.com/squid-cache/squid/pull/585
- https://github.com/squid-cache/squid/commit/eeebf0f37a72a2de08348e85ae34b02c34e9a811
- http://www.openwall.com/lists/oss-security/2020/04/23/2
- https://bugzilla.suse.com/show_bug.cgi?id=1170313
- DSA-4682 vendor-advisory
- openSUSE-SU-2020:0623 vendor-advisory
- GLSA-202005-05 vendor-advisory
- FEDORA-2020-848065cc4c vendor-advisory
- FEDORA-2020-a6a921a591 vendor-advisory
- FEDORA-2020-56e809930e vendor-advisory
- USN-4356-1 vendor-advisory
- [debian-lts-announce] 20200710 [SECURITY] [DLA 2278-1] squid3 security update mailing-list
- https://security.netapp.com/advisory/ntap-20210304-0004/