An issue was discovered in Squid 4.0.23 through 4.7.
Priority HIGH 69CWE-787Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.
Summary
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.
Why it matters now
EPSS 0.49037 98th percentileScored 2026-11-07
Fix Fixed Red Hat: 1 advisory
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 17
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* | 4.0.23 – 4.7 | Vulnerable | squid-cache |
| cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:* | 29 | Vulnerable | Fedoraproject |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* | 16.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* | 18.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:* | 19.04 | Vulnerable | Canonical |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_eus:8.1:*:*:*:*:*:*:* | 8.1 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:* | 8.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:* | 8.4 | Vulnerable | Red Hat |
- cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* Versions 4.0.23 – 4.7 Vulnerable ·squid-cache
- cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:* Versions 29 Vulnerable ·Fedoraproject
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* Versions 16.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:* Versions 19.04 Vulnerable ·Canonical
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_eus:8.1:*:*:*:*:*:*:* Versions 8.1 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
Show 7 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:* | 8.6 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:* | 8.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:* | 8.4 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_aus:8.6:*:*:*:*:*:*:* | 8.6 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:* | 8.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_tus:8.4:*:*:*:*:*:*:* | 8.4 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:* | 8.6 | Vulnerable | Red Hat |
- cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_aus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_tus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
Remediation
Red Hat 1 advisory
- RHSA-2019:2593 Released 2019-09-03 · Red Hat rating Importantsquid:4 security update
- Red Hat Enterprise Linux AppStream (v. 8) libecap-1.0.1-2.module+el8.0.0+4045+70edde92.aarch64::squid:4, libecap-1.0.1-2.module+el8.0.0+4045+70edde92.ppc64le::squid:4, libecap-1.0.1-2.module+el8.0.0+4045+70edde92.s390x::squid:4 +11
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2019:2593 |
Not affected: 3 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2019-12527
- 2026-10-03 Alias added: GHSA-8x4r-gffh-rx7f
References
Patch 2
Sources
- CVE-2019-12527 · CVE Program
- CVE-2019-12527 · NVD
- FIRST EPSS
- GHSA-8x4r-gffh-rx7f · GitHub Advisory Database · CC BY 4.0
- CVE-2019-12527 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences