Read the docs
TI-2019-13515 Aliases CVE-2019-18677GHSA-mm65-p7g9-c5hr

An issue was discovered in Squid 3.x and 4.x through 4.8 when the append_domain setting…

Priority LOW 34CWE-352Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Tampering
Confidentiality · integrity · availability
Low · Low · None
Fix status
Partial Red Hat: 1 fixed, 3 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-352.

Summary

An issue was discovered in Squid 3.x and 4.x through 4.8 when the append_domain setting is used (because the appended characters do not properly interact with hostname length restrictions). Due to incorrect message processing, it can inappropriately redirect traffic to origins it should not be delivered to.

Why it matters now

EPSS 0.03933 90th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 3 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 15

CPEVersionsRoleVendor
cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*2.0 – 2.7; 3.0 – 3.5.28; 4.0 – 4.8Vulnerablesquid-cache
cpe:2.3:a:squid-cache:squid:2.7:stable2:*:*:*:*:*:*2.7 stable2Vulnerablesquid-cache
cpe:2.3:a:squid-cache:squid:2.7:stable3:*:*:*:*:*:*2.7 stable3Vulnerablesquid-cache
cpe:2.3:a:squid-cache:squid:2.7:stable4:*:*:*:*:*:*2.7 stable4Vulnerablesquid-cache
cpe:2.3:a:squid-cache:squid:2.7:stable5:*:*:*:*:*:*2.7 stable5Vulnerablesquid-cache
cpe:2.3:a:squid-cache:squid:2.7:stable6:*:*:*:*:*:*2.7 stable6Vulnerablesquid-cache
cpe:2.3:a:squid-cache:squid:2.7:stable7:*:*:*:*:*:*2.7 stable7Vulnerablesquid-cache
cpe:2.3:a:squid-cache:squid:2.7:stable8:*:*:*:*:*:*2.7 stable8Vulnerablesquid-cache
cpe:2.3:a:squid-cache:squid:2.7:stable9:*:*:*:*:*:*2.7 stable9Vulnerablesquid-cache
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*16.04VulnerableCanonical
  • cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* Versions 2.0 – 2.7; 3.0 – 3.5.28; 4.0 – 4.8 Vulnerable ·squid-cache
  • cpe:2.3:a:squid-cache:squid:2.7:stable2:*:*:*:*:*:* Versions 2.7 stable2 Vulnerable ·squid-cache
  • cpe:2.3:a:squid-cache:squid:2.7:stable3:*:*:*:*:*:* Versions 2.7 stable3 Vulnerable ·squid-cache
  • cpe:2.3:a:squid-cache:squid:2.7:stable4:*:*:*:*:*:* Versions 2.7 stable4 Vulnerable ·squid-cache
  • cpe:2.3:a:squid-cache:squid:2.7:stable5:*:*:*:*:*:* Versions 2.7 stable5 Vulnerable ·squid-cache
  • cpe:2.3:a:squid-cache:squid:2.7:stable6:*:*:*:*:*:* Versions 2.7 stable6 Vulnerable ·squid-cache
  • cpe:2.3:a:squid-cache:squid:2.7:stable7:*:*:*:*:*:* Versions 2.7 stable7 Vulnerable ·squid-cache
  • cpe:2.3:a:squid-cache:squid:2.7:stable8:*:*:*:*:*:* Versions 2.7 stable8 Vulnerable ·squid-cache
  • cpe:2.3:a:squid-cache:squid:2.7:stable9:*:*:*:*:*:* Versions 2.7 stable9 Vulnerable ·squid-cache
  • cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* Versions 16.04 Vulnerable ·Canonical
Show 5 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*18.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:*19.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*19.10VulnerableCanonical
cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*30VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*31VulnerableFedoraproject
  • 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

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 →

ProductStatusPlan or fix
Red Hat Enterprise Linux 5AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2020:4743

Timeline

  1. 2026-10-02 Threatist record created from CVE-2019-18677
  2. 2026-10-03 Alias added: GHSA-mm65-p7g9-c5hr

References

Patch 1

Advisory 7

Other 3

Sources

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