Description
Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a NULL pointer dereference bug Squid is vulnerable to a Denial of Service attack against Squid's Gopher gateway. The gopher protocol is always available and enabled in Squid prior to Squid 6.0.1. Responses triggering this bug are possible to be received from any gopher server, even those without malicious intent. Gopher support has been removed in Squid version 6.0.1. Users are advised to upgrade. Users unable to upgrade should reject all gopher URL requests.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| squid-cache | squid | < 6.0.1 | — |
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 | 6.1-1 | — |
| Debian 13 | squid | 6.1-1 | — |
| Debian 12 | squid | 5.7-2+deb12u5 | — |
| Debian 11 | squid | 4.13-10+deb11u5 | DLA-4312-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | squid | 5.7-0ubuntu0.22.04.2 | USN-6500-1 |
| Ubuntu 20.04 LTS | squid | 4.10-1ubuntu1.8 | USN-6500-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | squid3 | 3.5.27-1ubuntu1.14+esm1 | USN-6500-2 |
| Ubuntu Pro 16.04 LTS | squid3 | 3.5.12-1ubuntu7.16+esm2 | USN-6500-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | squid | 7:5.5-6.el9_3.5 | RHSA-2024:0071 |
| RHEL 8 | libecap +1 | 1.0.1-2.module+el8.9.0+19703+a1da7223 | RHSA-2024:0046 |
| RHEL 8 | squid | 7:4.15-7.module+el8.9.0+20975+25f17541.5 | RHSA-2024:0046 |
| RHEL 7 | squid +2 | 7:3.5.20-17.el7_9.10 | RHSA-2024:1787 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.2 EUS | squid | 7:5.5-5.el9_2.3 | RHSA-2024:0072 |
| RHEL 9.0 EUS | squid | 7:5.2-1.el9_0.4 | RHSA-2024:1153 |
| RHEL 8.8 EUS | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2024:0397 |
| RHEL 8.8 EUS | squid | 7:4.15-6.module+el8.8.0+21068+0ecbc070.3 | RHSA-2024:0397 |
| RHEL 8.6 EUS | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2024:0771 |
| RHEL 8.6 EUS | squid | 7:4.15-3.module+el8.6.0+21069+a1561e3d.4 | RHSA-2024:0771 |
| RHEL 8.4 TUS | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2024:0773 |
| RHEL 8.4 TUS | squid | 7:4.11-4.module+el8.4.0+21174+3894a031.6 | RHSA-2024:0773 |
| RHEL 8.4 E4S | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2024:0773 |
| RHEL 8.4 E4S | squid | 7:4.11-4.module+el8.4.0+21174+3894a031.6 | RHSA-2024:0773 |
| RHEL 8.4 AUS | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2024:0773 |
| RHEL 8.4 AUS | squid | 7:4.11-4.module+el8.4.0+21174+3894a031.6 | RHSA-2024:0773 |
| RHEL 8.2 TUS | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2024:0772 |
| RHEL 8.2 TUS | squid | 7:4.4-8.module+el8.2.0+21173+22259b09.7 | RHSA-2024:0772 |
| RHEL 8.2 E4S | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2024:0772 |
| RHEL 8.2 E4S | squid | 7:4.4-8.module+el8.2.0+21173+22259b09.7 | RHSA-2024:0772 |
| RHEL 8.2 AUS | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2024:0772 |
| RHEL 8.2 AUS | squid | 7:4.4-8.module+el8.2.0+21173+22259b09.7 | RHSA-2024:0772 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | squid | 7:5.5-6.el9_3.5 | ALSA-2024:0071 |
| AlmaLinux 8 | libecap +1 | 1.0.1-2.module_el8.6.0+2741+01592ae8 | ALSA-2024:0046 |
| AlmaLinux 8 | squid | 7:4.15-7.module_el8.9.0+3708+6acaac63.5 | ALSA-2024:0046 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | libecap | 1.0.1-2.module+el8.9.0+1437+df5ea8f0 | RLSA-2024:0046 |
| Rocky Linux 8 | squid | 7:4.15-7.module+el8.9.0+1568+6d4fd5d4.1 | RLSA-2024:0046 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP5 | squid | 5.7-150400.3.15.1 | SUSE-SU-2023:4544-1 |
| SLES 15 SP4 | squid | 5.7-150400.3.15.1 | SUSE-SU-2023:4544-1 |
| SLES 15 SP3 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
| SLES 15 SP2 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
| SLES 15 SP1 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | squid | 4.17-4.33.1 | SUSE-SU-2023:4545-1 |
| SLES for SAP 15 SP3 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
| SLES for SAP 15 SP2 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
| SLES for SAP 15 SP1 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
| SLES for SAP 12 SP5 | squid | 4.17-4.33.1 | SUSE-SU-2023:4545-1 |
| SLE HPC 15 SP3 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
| SLE HPC 15 SP2 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
| SLE HPC 15 SP1 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
| SUSE Enterprise Storage 7.1 | squid | 4.17-150000.5.41.1 | SUSE-SU-2023:4589-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.5 | squid | 5.7-150400.3.15.1 | SUSE-SU-2023:4544-1 |
| openSUSE Leap 15.4 | squid | 5.7-150400.3.15.1 | SUSE-SU-2023:4544-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | squid | 7:5.8-1.amzn2023.0.2 | ALAS2023-2023-429 |
| Amazon Linux 2 | squid +2 | 7:3.5.20-17.amzn2.7.14 | ALAS2-2023-2354 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | squid | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | squid | 7:5.5-6.0.1.el9_3.5 | ELSA-2024-0071 |
| Oracle Linux 8 | libecap +1 | 1.0.1-2.module+el8.9.0+90083+f7556140 | ELSA-2024-0046 |
| Oracle Linux 8 | squid | 7:4.15-7.module+el8.9.0+90111+615ac445.5 | ELSA-2024-0046 |
| Oracle Linux 7 | squid +2 | 7:3.5.20-17.0.1.el7_9.10 | ELSA-2024-1787 |
Advisories 25
- ALSA-2024:0071 Important: squid security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2024:0046 Important: squid:4 security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2024:1153 Red Hat Security Advisory: squid security update Red Hat Security Advisories (RHSA) · Jul 12, 2026
- RHSA-2024:0772 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Jul 12, 2026
- RHSA-2024:0773 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Jul 12, 2026
- RHSA-2024:0771 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Jul 12, 2026
- RHSA-2024:0397 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Jul 12, 2026
- RHSA-2024:0072 Red Hat Security Advisory: squid security update Red Hat Security Advisories (RHSA) · Jul 12, 2026
- RHSA-2024:1787 Red Hat Security Advisory: squid security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2024:0071 Red Hat Security Advisory: squid security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2024:0046 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-6500-2 squid3 vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- USN-6500-1 squid vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- RLSA-2024:0046 Important: squid:4 security update Rocky Linux Security Advisories · Feb 5, 2026
- SUSE-SU-2023:4545-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:4589-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2023-2837 Squid: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Nov 18, 2025
- DLA-4312-1 squid - security update Debian Security (DSA / DLA) · Sep 27, 2025
- SUSE-SU-2023:4544-1 Security update for squid SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2024-1248 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 21, 2024
- ELSA-2024-1787 Important: squid security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Apr 11, 2024
- ELSA-2024-0071 Important: squid security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jan 10, 2024
- ELSA-2024-0046 Important: squid:4 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jan 4, 2024
- ALAS2023-2023-429 Important: squid security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Dec 6, 2023
- ALAS2-2023-2354 Important: squid security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Dec 4, 2023
References
- https://github.com/squid-cache/squid/security/advisories/GHSA-cg5h-v6vc-w33f
- https://github.com/squid-cache/squid/commit/6ea12e8fb590ac6959e9356a81aa3370576568c3
- https://security.netapp.com/advisory/ntap-20231214-0006/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MEV66D3PAAY6K7TWDT3WZBLCPLASFJDC/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/A5QASTMCUSUEW3UOMKHZJB3FTONWSRXS/