Description
An issue was discovered in Squid before 4.10. Due to incorrect buffer management, a remote client can cause a buffer overflow in a Squid instance acting as a reverse proxy.
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 | 4.10-1 | — |
| Debian 13 | squid | 4.10-1 | — |
| Debian 12 | squid | 4.10-1 | — |
| 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 | 4.9-2ubuntu4 | — |
| Ubuntu 18.04 LTS | squid3 | 3.5.27-1ubuntu1.5 | USN-4289-1 |
| Ubuntu 16.04 LTS | squid3 | 3.5.12-1ubuntu7.10 | USN-4289-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | libecap +1 | 1.0.1-2.module+el8.1.0+4044+36416a77 | RHSA-2020:4743 |
| RHEL 8 | squid | 7:4.11-3.module+el8.3.0+7851+7808b5f9 | RHSA-2020:4743 |
| RHEL 7 | squid +2 | 7:3.5.20-17.el7_9.4 | RHSA-2020:4082 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | libecap +1 | 1.0.1-2.module_el8.6.0+2741+01592ae8 | ALSA-2020:4743 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | libecap | 1.0.1-2.module+el8.4.0+404+316a0dc5 | RLSA-2020:4743 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | squid | 4.10-5.14.1 | SUSE-SU-2020:0493-1 |
| SLES 12 SP5 | squid | 4.10-4.6.1 | SUSE-SU-2020:0487-1 |
| SLES 12 SP4 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
| SLES 12 SP3 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
| SLES 12 SP2 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP4 | squid3 | 3.1.23-8.16.37.12.1 | SUSE-SU-2020:14460-1 |
| SLES for SAP 12 SP5 | squid | 4.10-4.6.1 | SUSE-SU-2020:0487-1 |
| SLES for SAP 12 SP4 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
| SLES for SAP 12 SP3 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
| SLES for SAP 12 SP2 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
| SUSE OpenStack Cloud Crowbar 8 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
| SUSE OpenStack Cloud 8 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
| SUSE OpenStack Cloud 7 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
| 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 | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
| SUSE Enterprise Storage 5 | squid | 3.5.21-26.20.1 | SUSE-SU-2020:0661-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.1 | squid | 4.10-lp151.2.11.1 | openSUSE-SU-2020:0606-1, openSUSE-SU-2020:0307-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | squid | 4.10-r0 | — |
| Alpine v3.23 | squid | 4.10-r0 | — |
| Alpine v3.22 | squid | 4.10-r0 | — |
| Alpine v3.21 | squid | 4.10-r0 | — |
| Alpine v3.20 | squid | 4.10-r0 | — |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | squid | 4.10-r0 | — |
| Alpine v3.18 | squid | 4.10-r0 | — |
| Alpine v3.17 | squid | 4.10-r0 | — |
| Alpine v3.16 | squid | 4.10-r0 | — |
| Alpine v3.15 | squid | 4.10-r0 | — |
| Alpine v3.14 | squid | 4.10-r0 | — |
| Alpine v3.13 | squid | 4.10-r0 | — |
| Alpine v3.12 | squid | 4.10-r0 | — |
| Alpine v3.11 | squid | 4.10-r0 | — |
| Alpine v3.10 | squid | 4.10-r0 | — |
| Alpine v3.9 | squid | 4.10-r0 | — |
| Alpine v3.8 | squid | 3.5.27-r4 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | squid +2 | 7:3.5.20-15.amzn2.1.1 | ALAS2-2020-1486 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | libecap +1 | 1.0.1-2.module+el8.3.0+7819+eb7d4ef6 | ELSA-2020-4743 |
| Oracle Linux 8 | squid | 7:4.11-3.module+el8.3.0+7819+eb7d4ef6 | ELSA-2020-4743 |
| Oracle Linux 7 | squid +2 | 7:3.5.20-17.el7_9.4 | ELSA-2020-4082 |
Advisories 17
- ALSA-2020:4743 Moderate: squid:4 security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2020:4743 Red Hat Security Advisory: squid:4 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jul 4, 2026
- RHSA-2020:4082 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-4289-1 squid, squid3 vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- RLSA-2020:4743 Moderate: squid:4 security, bug fix, and enhancement update Rocky Linux Security Advisories · Feb 4, 2026
- openSUSE-SU-2020:0307-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0661-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0493-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0606-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0487-1 Security update for squid SUSE / openSUSE Security Updates · May 2, 2025
- SUSE-SU-2020:14460-1 Security update for squid3 SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2023-1361 Squid: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 8, 2023
- ELSA-2020-4743 Moderate: squid:4 security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 10, 2020
- ELSA-2020-4082 Important: squid security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Oct 8, 2020
- ALAS2-2020-1486 Moderate: squid security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Sep 2, 2020
References
- http://www.squid-cache.org/Advisories/SQUID-2020_1.txt
- http://www.squid-cache.org/Versions/v4/changesets/squid-4-d8e4715992d0e530871519549add5519cbac0598.patch
- http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-8e657e835965c3a011375feaa0359921c5b3e2dd.patch
- http://www.squid-cache.org/Versions/v4/changesets/squid-4-b3a0719affab099c684f1cd62b79ab02816fa962.patch
- http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_1.patch
- http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2020_1.patch
- USN-4289-1 vendor-advisory
- openSUSE-SU-2020:0307 vendor-advisory
- GLSA-202003-34 vendor-advisory
- FEDORA-2020-ab8e7463ab vendor-advisory
- FEDORA-2020-790296a8f4 vendor-advisory
- openSUSE-SU-2020:0606 vendor-advisory
- DSA-4682 vendor-advisory
- [debian-lts-announce] 20200710 [SECURITY] [DLA 2278-1] squid3 security update mailing-list
- https://security.netapp.com/advisory/ntap-20210304-0002/