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TI-2023-25211 Aliases CVE-2023-46728

SQUID-2021:8 Denial of Service in Gopher gateway

Priority MEDIUM 45CWE-476Published · Updated

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: 16 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-476.

Summary

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a NULL pointer dereference bug Squid is vulnerable to a Denial of Service attack against Squid's Gopher gateway. The gopher protocol is always available and enabled in Squid prior to Squid 6.0.1. Responses triggering this bug are possible to be received from any gopher server, even those without malicious intent. Gopher support has been removed in Squid version 6.0.1. Users are advised to upgrade. Users unable to upgrade should reject all gopher URL requests.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.03775 90th percentileScored 2026-11-07
Fix Partial squid (squid-cache): 6.0.1Red Hat: 9 advisoriesRed Hat: 16 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
squid-cachesquidbefore 6.0.16.0.1Patch availableCNA
  • squid Vendorsquid-cache Affected before 6.0.1 Fixed in 6.0.1 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*before 6.0.1Vulnerablesquid-cache
  • cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* Versions before 6.0.1 Vulnerable ·squid-cache

Remediation

  • Fix · CNA squid (squid-cache) Fixed in 6.0.1

Red Hat 9 advisories

  • RHSA-2024:1787 Released 2024-04-11 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux Server (v. 7) squid-7:3.5.20-17.el7_9.10, squid-migration-script-7:3.5.20-17.el7_9.10
    • Red Hat Enterprise Linux Server Optional (v. 7) squid-sysvinit-7:3.5.20-17.el7_9.10
    • Red Hat Enterprise Linux Workstation (v. 7) squid-7:3.5.20-17.el7_9.10, squid-migration-script-7:3.5.20-17.el7_9.10
    • Red Hat Enterprise Linux Workstation Optional (v. 7) squid-sysvinit-7:3.5.20-17.el7_9.10
  • RHSA-2024:1153 Released 2024-03-05 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.0) squid-7:5.2-1.el9_0.4
  • RHSA-2024:0771 Released 2024-02-12 · Red Hat rating Important
    squid:4 security update
    • Red Hat Enterprise Linux AppStream EUS (v.8.6) 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
Show 6 more Red Hat advisories
  • RHSA-2024:0773 Released 2024-02-12 · Red Hat rating Important
    squid:4 security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
    • Red Hat Enterprise Linux AppStream E4S (v.8.4) 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.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +5
    • Red Hat Enterprise Linux AppStream TUS (v.8.4) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
  • RHSA-2024:0772 Released 2024-02-12 · Red Hat rating Important
    squid:4 security update
    • Red Hat Enterprise Linux AppStream AUS (v. 8.2) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
    • Red Hat Enterprise Linux AppStream E4S (v. 8.2) 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.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +5
    • Red Hat Enterprise Linux AppStream TUS (v. 8.2) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
  • RHSA-2024:0397 Released 2024-01-24 · Red Hat rating Important
    squid:4 security update
    • Red Hat Enterprise Linux AppStream EUS (v.8.8) 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
  • RHSA-2024:0071 Released 2024-01-08 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream (v. 9) squid-7:5.5-6.el9_3.5
  • RHSA-2024:0072 Released 2024-01-08 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.2) squid-7:5.5-5.el9_2.3
  • RHSA-2024:0046 Released 2024-01-03 · Red Hat rating Important
    squid:4 security update
    • Red Hat Enterprise Linux AppStream (v. 8) libecap-1.0.1-2.module+el8.9.0+19703+a1da7223.aarch64::squid:4, libecap-1.0.1-2.module+el8.9.0+19703+a1da7223.ppc64le::squid:4, libecap-1.0.1-2.module+el8.9.0+19703+a1da7223.s390x::squid:4 +11

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2024:0046
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2024:0071
Red Hat Enterprise Linux AppStream AUS (v. 8.2)Fixed RHSA-2024:0772
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2024:0773
Red Hat Enterprise Linux AppStream E4S (v. 8.2)Fixed RHSA-2024:0772
Red Hat Enterprise Linux AppStream E4S (v.8.4)Fixed RHSA-2024:0773
Red Hat Enterprise Linux AppStream EUS (v.8.6)Fixed RHSA-2024:0771
Red Hat Enterprise Linux AppStream EUS (v.8.8)Fixed RHSA-2024:0397
Red Hat Enterprise Linux AppStream EUS (v.9.0)Fixed RHSA-2024:1153
Red Hat Enterprise Linux AppStream EUS (v.9.2)Fixed RHSA-2024:0072
Red Hat Enterprise Linux AppStream TUS (v. 8.2)Fixed RHSA-2024:0772
Red Hat Enterprise Linux AppStream TUS (v.8.4)Fixed RHSA-2024:0773
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2024:1787
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2024:1787
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2024:1787
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2024:1787

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-46728

References

Patch 1

Advisory 1

Other 3

  • TI-2025-38486 Squid vulnerable to information disclosure via authentication credential leakage in error handling CVSS 3.1CRITICAL 10.0
  • TI-2024-16845 Denial of Service in HTTP Header parser in squid proxy CVSS 3.1HIGH 7.5
  • TI-2024-16566 SQUID-2024:1 Denial of Service in HTTP Chunked Decoding CVSS 3.1HIGH 8.6
  • TI-2023-26921 Denial of Service in HTTP Message Processing in Squid CVSS 3.1HIGH 8.6
  • TI-2023-27496 SQUID-2023:10 Denial of Service in HTTP Request parsing CVSS 3.1HIGH 8.6
  • TI-2023-25306 Squid: denial of service in http digest authentication CVSS 3.1HIGH 8.6
See all 110 →

Sources

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