Description
An issue was discovered in Squid 4.0.23 through 4.7. When checking Basic Authentication with HttpHeader::getAuth, Squid uses a global buffer to store the decoded data. Squid does not check that the decoded length isn't greater than the buffer, leading to a heap-based buffer overflow with user controlled data.
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 | 4.8-1 | — |
| Debian 13 | squid | 4.8-1 | — |
| Debian 12 | squid | 4.8-1 | — |
| Debian 10 | squid | 4.6-1+deb10u1 | DSA-4507-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | libecap +1 | 1.0.1-2.module+el8.0.0+4045+70edde92 | RHSA-2019:2593 |
| RHEL 8 | squid | 7:4.4-5.module+el8.0.0+4045+70edde92 | RHSA-2019:2593 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | libecap +1 | 1.0.1-2.module_el8.6.0+2741+01592ae8 | ALSA-2019:2593 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | libecap | 1.0.1-2.module+el8.4.0+404+316a0dc5 | RLSA-2019:2593 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | squid | 4.9-5.11.1 | SUSE-SU-2019:2975-1 |
| SLES 15 | squid | 4.9-5.11.1 | SUSE-SU-2019:2975-1 |
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 | 4.9-lp151.2.7.1 | openSUSE-SU-2019:2541-1 |
| openSUSE Leap 15.0 | squid | 4.9-lp150.13.1 | openSUSE-SU-2019:2540-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | libecap +1 | 1.0.1-2.module+el8.0.0+5324+ea04b9c2 | ELSA-2019-2593 |
| Oracle Linux 8 | squid | 7:4.4-5.module+el8.0.0+5324+ea04b9c2 | ELSA-2019-2593 |
Advisories 10
- ALSA-2019:2593 Important: squid:4 security update AlmaLinux Security Advisories · Oct 29, 2026
- DSA-4507-1 squid - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2019:2593 Important: squid:4 security update Rocky Linux Security Advisories · Feb 5, 2026
- openSUSE-SU-2024:11403-1 squid-4.16-1.5 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:2541-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:2975-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:2540-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2019:2593 Red Hat Security Advisory: squid:4 security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- WID-SEC-2023-2486 Squid: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 26, 2023
- ELSA-2019-2593 Important: squid:4 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Sep 3, 2019
References
- http://www.squid-cache.org/Versions/v4/changesets/
- https://github.com/squid-cache/squid/commits/v4
- http://www.squid-cache.org/Versions/v4/changesets/squid-4-7f73e9c5d17664b882ed32590e6af310c247f320.patch
- 109143 vdb-entry
- USN-4065-1 vendor-advisory
- FEDORA-2019-cb50bcc189 vendor-advisory
- DSA-4507 vendor-advisory
- 20190825 [SECURITY] [DSA 4507-1] squid security update mailing-list
- RHSA-2019:2593 vendor-advisory
- openSUSE-SU-2019:2540 vendor-advisory
- openSUSE-SU-2019:2541 vendor-advisory