TI-2019-13514 Aliases CVE-2019-18676 GHSA-chw7-jm99-chw8

An issue was discovered in Squid 3.x and 4.x through 4.8.

MEDIUM 45CWE-787Published 2019-11-26 · Updated 2024-08-05

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 1 fixed, 2 without a fix

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 3.x and 4.x through 4.8. Due to incorrect input validation, there is a heap-based buffer overflow that can result in Denial of Service to all clients using the proxy. Severity is high due to this vulnerability occurring before normal security checks; any remote client that can reach the proxy port can trivially perform the attack via a crafted URI scheme.

Why it matters now

EPSS 0.0918 95th percentileScored 2026-11-07

Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 2 without a fix

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 · 10

CPE	Versions	Role	Vendor
cpe:2.3:a:squid-cache:squid::::::::	3.0 – 3.5.28; 4.0 – 4.8	Vulnerable	squid-cache
cpe:2.3:o:canonical:ubuntu_linux:16.04::::lts:::	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:canonical:ubuntu_linux:19.10:::::::*	19.10	Vulnerable	Canonical
cpe:2.3:o:fedoraproject:fedora:30:::::::*	30	Vulnerable	Fedoraproject
cpe:2.3:o:fedoraproject:fedora:31:::::::*	31	Vulnerable	Fedoraproject
cpe:2.3:o:debian:debian_linux:9.0:::::::*	9.0	Vulnerable	Debian
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:a:squid-cache:squid:*:*:*:*:*:*:*:* Versions 3.0 – 3.5.28; 4.0 – 4.8 Vulnerable ·squid-cache
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* 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:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:* Versions 19.10 Vulnerable ·Canonical
cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:* Versions 30 Vulnerable ·Fedoraproject
cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:* Versions 31 Vulnerable ·Fedoraproject
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
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

Remediation

Red Hat 1 advisory

RHSA-2020:4743 Released 2020-11-04 · Red Hat rating Moderate
squid:4 security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.aarch64::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.s390x::squid:4 +11

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 6	Affected	No fix planned: Out of support scope
Red Hat Enterprise Linux 7	Affected	No fix planned: Will not fix
Red Hat Enterprise Linux AppStream (v. 8)	Fixed	RHSA-2020:4743

Not affected: 1 product

Red Hat Enterprise Linux 5

Timeline

2026-10-02 Threatist record created from CVE-2019-18676
2026-10-03 Alias added: GHSA-chw7-jm99-chw8

References

Patch 2

Advisory 8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences