Description
An issue was discovered in Squid through 4.13 and 5.x through 5.0.4. Due to improper input validation, it allows a trusted client to perform HTTP Request Smuggling and access services otherwise forbidden by the security controls. This occurs for certain uri_whitespace configuration settings.
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 | 4.13-8 | — |
| Debian 13 | squid | 4.13-8 | — |
| Debian 12 | squid | 4.13-8 | — |
| Debian 10 | squid | 4.6-1+deb10u5 | DSA-4873-1 |
| Debian 9 | squid3 | 3.5.23-5+deb9u6 | DLA-2598-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | squid | 4.10-1ubuntu1.3 | USN-4895-1 |
| Ubuntu 18.04 LTS | squid3 | 3.5.27-1ubuntu1.10 | USN-4895-1 |
| Ubuntu 16.04 LTS | squid3 | 3.5.12-1ubuntu7.16 | USN-4895-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2021:1979 |
| RHEL 8 | squid | 7:4.11-4.module+el8.4.0+10676+a969168e.2 | RHSA-2021:1979 |
| RHEL 7 | squid +2 | 7:3.5.20-17.el7_9.6 | RHSA-2021:1135 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.2 EUS | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2021:2025 |
| RHEL 8.2 EUS | squid | 7:4.4-8.module+el8.2.0+10583+6e4ac934.3 | RHSA-2021:2025 |
| RHEL 8.1 EUS | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2021:2025 |
| RHEL 8.1 EUS | squid | 7:4.4-8.module+el8.1.0+10584+c769fd35.3 | RHSA-2021:2025 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | libecap +1 | 1.0.1-2.module_el8.6.0+2741+01592ae8 | ALSA-2021:1979 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | libecap | 1.0.1-2.module+el8.4.0+404+316a0dc5 | RLSA-2021:1979 |
| Rocky Linux 8 | squid | 7:4.11-4.module+el8.4.0+404+316a0dc5.2 | RLSA-2021:1979 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SLES 15 SP2 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SLES 15 SP1 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SLES 15 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SLES 12 SP5 | squid | 4.15-4.18.1 | SUSE-SU-2021:1838-1 |
Show 17 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | squid | 3.5.21-26.35.1 | SUSE-SU-2022:2392-1 |
| SLES 12 SP3 | squid | 3.5.21-26.35.1 | SUSE-SU-2022:2392-1 |
| SLES 12 SP2 | squid | 3.5.21-26.35.1 | SUSE-SU-2022:2392-1 |
| SLES 11 SP4 | squid3 | 3.1.23-8.16.37.18.1 | SUSE-SU-2022:14914-1 |
| SLES for SAP 15 SP1 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SLES for SAP 15 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SLES for SAP 12 SP5 | squid | 4.15-4.18.1 | SUSE-SU-2021:1838-1 |
| SLES for SAP 12 SP4 | squid | 3.5.21-26.35.1 | SUSE-SU-2022:2392-1 |
| SLE HPC 15 SP1 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SLE HPC 15 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SUSE OpenStack Cloud Crowbar 9 | squid | 3.5.21-26.35.1 | SUSE-SU-2022:2392-1 |
| SUSE OpenStack Cloud 9 | squid | 3.5.21-26.35.1 | SUSE-SU-2022:2392-1 |
| SUSE Manager Server 4.0 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SUSE Manager Retail Branch Server 4.0 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SUSE Manager Proxy 4.0 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | squid3 | 3.1.23-8.16.37.18.1 | SUSE-SU-2022:14914-1 |
| SUSE Enterprise Storage 6 | squid | 4.15-5.26.1 | SUSE-SU-2021:1961-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | squid | 4.16-1.5 | openSUSE-SU-2024:11403-1 |
| openSUSE Leap 15.3 | squid | 4.15-5.26.1 | openSUSE-SU-2021:1961-1 |
| openSUSE Leap 15.2 | squid | 4.15-lp152.2.9.1 | openSUSE-SU-2021:0879-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | squid | 5.0.5-r0 | — |
| Alpine v3.23 | squid | 5.0.5-r0 | — |
| Alpine v3.22 | squid | 5.0.5-r0 | — |
| Alpine v3.21 | squid | 5.0.5-r0 | — |
| Alpine v3.20 | squid | 5.0.5-r0 | — |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | squid | 5.0.5-r0 | — |
| Alpine v3.18 | squid | 5.0.5-r0 | — |
| Alpine v3.17 | squid | 5.0.5-r0 | — |
| Alpine v3.16 | squid | 5.0.5-r0 | — |
| Alpine v3.15 | squid | 5.0.5-r0 | — |
| Alpine v3.14 | squid | 5.0.5-r0 | — |
| Alpine v3.13 | squid | 5.0.5-r0 | — |
| Alpine v3.12 | squid | 4.14-r0 | — |
| Alpine v3.11 | squid | 4.14-r0 | — |
| Alpine v3.10 | squid | 4.14-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | squid +2 | 7:3.5.20-17.amzn2.6.1 | ALAS2-2021-1631 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | libecap +1 | 1.0.1-2.module+el8.3.0+7819+eb7d4ef6 | ELSA-2021-1979 |
| Oracle Linux 8 | squid | 7:4.11-4.module+el8.4.0+20173+36853f3f.2 | ELSA-2021-1979 |
| Oracle Linux 7 | squid +2 | 7:3.5.20-17.el7_9.6 | ELSA-2021-1135 |
Advisories 19
- ALSA-2021:1979 Important: squid:4 security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2021:1135 Red Hat Security Advisory: squid security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-4873-1 squid - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2598-1 squid3 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-4895-1 squid, squid3 vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- RLSA-2021:1979 Important: squid:4 security update Rocky Linux Security Advisories · Feb 5, 2026
- SUSE-SU-2022:14914-1 Security update for squid3 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:2392-1 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
- SUSE-SU-2021:1961-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0879-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1961-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1838-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2021:2025 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:1979 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- WID-SEC-2022-0670 Squid: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen BSI CERT-Bund (WID) · Sep 27, 2023
- ELSA-2021-1979 Important: squid:4 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 26, 2021
- ALAS2-2021-1631 Important: squid security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 21, 2021
- ELSA-2021-1135 Important: squid security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Apr 9, 2021
References
- https://github.com/squid-cache/squid/security/advisories/GHSA-jvf6-h9gj-pmj6
- http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_11.patch
- http://www.squid-cache.org/Versions/v5/changesets/SQUID-2020_11.patch
- DSA-4873 vendor-advisory
- FEDORA-2021-ecb24e0b9d vendor-advisory
- FEDORA-2021-7d86bec29e vendor-advisory
- FEDORA-2021-76f09062a7 vendor-advisory
- GLSA-202105-14 vendor-advisory
- https://security.netapp.com/advisory/ntap-20210727-0010/