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Fencer Vulns
high 7.5

CVE-2023-46728 json

SQUID-2021:8 Denial of Service in Gopher gateway

published 2023-11-06 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-50910

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
3.8%
EPSS 3.8% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

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.

Patch / fix

  • squid-cache squid 6.0.1
  • squid Debian 12 5.7-2+deb12u5
  • squid Debian 14, Debian 13 6.1-1

debian advisories DEBIAN-CVE-2023-46728

  • squid Ubuntu 20.04 LTS 4.10-1ubuntu1.8
  • squid Ubuntu 22.04 LTS 5.7-0ubuntu0.22.04.2
  • squid3 Ubuntu Pro 16.04 LTS 3.5.12-1ubuntu7.16+esm2
  • squid3 Ubuntu Pro 18.04 LTS 3.5.27-1ubuntu1.14+esm1

ubuntu advisories UBUNTU-CVE-2023-46728

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • squid RHEL 7 7:3.5.20-17.el7_9.10
  • squid-sysvinit RHEL 7 7:3.5.20-17.el7_9.10
  • squid-migration-script RHEL 7 7:3.5.20-17.el7_9.10
  • squid RHEL 9 7:5.5-6.el9_3.5
  • squid RHEL 8 7:4.15-7.module+el8.9.0+20975+25f17541.5
  • libecap RHEL 8 1.0.1-2.module+el8.9.0+19703+a1da7223
  • squid RHEL 9.0 EUS 7:5.2-1.el9_0.4
  • squid RHEL 8.6 EUS 7:4.15-3.module+el8.6.0+21069+a1561e3d.4

red hat advisories RHSA-2024:1787RHSA-2024:1153RHSA-2024:0771RHSA-2024:0772RHSA-2024:0773RHSA-2024:0397

  • squid SLES for SAP 15 SP3, SLES for SAP 15 SP2, SLES for SAP 15 SP1 +8 more 4.17-150000.5.41.1
  • squid SLES for SAP 12 SP5, SLES 12 SP5 4.17-4.33.1
  • squid SLE Module for Server Applications 15 SP5, SLE Module for Server Applications 15 SP4, openSUSE Leap 15.5 +1 more 5.7-150400.3.15.1

suse advisories SUSE-SU-2023:4589-1SUSE-SU-2023:4545-1SUSE-SU-2023:4544-1

  • squid AlmaLinux 9 7:5.5-6.el9_3.5
  • squid AlmaLinux 8 7:4.15-7.module_el8.9.0+3708+6acaac63.5
  • libecap AlmaLinux 8 1.0.1-2.module_el8.6.0+2741+01592ae8
  • libecap AlmaLinux 8 1.0.1-2.module_el8.6.0+3048+383bc947

almalinux advisories ALSA-2024:0071ALSA-2024:0046

  • squid Rocky Linux 8 7:4.15-7.module+el8.9.0+1568+6d4fd5d4.1
  • libecap Rocky Linux 8 1.0.1-2.module+el8.9.0+1437+df5ea8f0

rocky linux advisories RLSA-2024:0046

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-46728 updated cvss 7.5

squid: NULL pointer dereference in the gopher protocol code

  • Red Hat Enterprise Linux 6 squid, squid34
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) squid 4.15-7.module+el8.9.0+20975+25f17541.5, libecap 1.0.1-2.module+el8.9.0+19703+a1da7223
    fixed: vendor fix RHSA-2024:0046
  • Red Hat Enterprise Linux AppStream (v. 9) squid 5.5-6.el9_3.5
    fixed: vendor fix RHSA-2024:0071
  • Red Hat Enterprise Linux AppStream AUS (v. 8.2) squid 4.4-8.module+el8.2.0+21173+22259b09.7, libecap 1.0.1-2.module+el8.1.0+4044+36416a77
    fixed: vendor fix RHSA-2024:0772
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.11-4.module+el8.4.0+21174+3894a031.6
    fixed: vendor fix RHSA-2024:0773
  • Red Hat Enterprise Linux AppStream E4S (v. 8.2) squid 4.4-8.module+el8.2.0+21173+22259b09.7, libecap 1.0.1-2.module+el8.1.0+4044+36416a77
    fixed: vendor fix RHSA-2024:0772
  • Red Hat Enterprise Linux AppStream E4S (v.8.4) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.11-4.module+el8.4.0+21174+3894a031.6
    fixed: vendor fix RHSA-2024:0773
  • Red Hat Enterprise Linux AppStream EUS (v.8.6) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.15-3.module+el8.6.0+21069+a1561e3d.4
    fixed: vendor fix RHSA-2024:0771
show 6 more
  • Red Hat Enterprise Linux AppStream EUS (v.8.8) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.15-6.module+el8.8.0+21068+0ecbc070.3
    fixed: vendor fix RHSA-2024:0397
  • Red Hat Enterprise Linux AppStream EUS (v.9.0) squid 5.2-1.el9_0.4
    fixed: vendor fix RHSA-2024:1153
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) squid 5.5-5.el9_2.3
    fixed: vendor fix RHSA-2024:0072
  • Red Hat Enterprise Linux AppStream TUS (v. 8.2) squid 4.4-8.module+el8.2.0+21173+22259b09.7, libecap 1.0.1-2.module+el8.1.0+4044+36416a77
    fixed: vendor fix RHSA-2024:0772
  • Red Hat Enterprise Linux AppStream TUS (v.8.4) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.11-4.module+el8.4.0+21174+3894a031.6
    fixed: vendor fix RHSA-2024:0773
  • Red Hat Enterprise Linux Server (v. 7) squid 3.5.20-17.el7_9.10, squid-sysvinit 3.5.20-17.el7_9.10, squid-migration-script 3.5.20-17.el7_9.10 Red Hat Enterprise Linux Server Optional (v. 7) squid 3.5.20-17.el7_9.10, squid-sysvinit 3.5.20-17.el7_9.10, squid-migration-script 3.5.20-17.el7_9.10 Red Hat Enterprise Linux Workstation (v. 7) squid 3.5.20-17.el7_9.10, squid-sysvinit 3.5.20-17.el7_9.10, squid-migration-script 3.5.20-17.el7_9.10 Red Hat Enterprise Linux Workstation Optional (v. 7) squid 3.5.20-17.el7_9.10, squid-sysvinit 3.5.20-17.el7_9.10, squid-migration-script 3.5.20-17.el7_9.10
    fixed: vendor fix RHSA-2024:1787

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
23 mo ago

Exploit prediction

3.77% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • squid-cache squid

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.