Skip to content
Fencer Vulns
critical 9.8

CVE-2019-12524 json

An issue was discovered in Squid through 4.7.

published 2020-04-15 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-4119

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.9%
EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to see if the request should be denied. Squid by default comes with rules to block access to the Cache Manager, which serves detailed server information meant for the maintainer. This rule is implemented via url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource.

Patch / fix

  • squid Debian 14, Debian 13, Debian 12 4.8-1

debian advisories DEBIAN-CVE-2019-12524

  • squid3 Ubuntu 18.04 LTS 3.5.27-1ubuntu1.7

ubuntu advisories UBUNTU-CVE-2019-12524

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 8 7:4.11-3.module+el8.3.0+7851+7808b5f9
  • libecap RHEL 8 1.0.1-2.module+el8.1.0+4044+36416a77

red hat advisories RHSA-2020:4743

  • squid3 SLES 11 SP4-LTSS, SLE Point of Sale 11 SP3 3.1.23-8.16.37.12.1
  • squid SLES for SAP 12 SP4, SLES for SAP 12 SP3, SLES for SAP 12 SP2 +10 more 3.5.21-26.23.1

suse advisories SUSE-SU-2020:14460-1SUSE-SU-2020:1227-1

  • libecap AlmaLinux 8 1.0.1-2.module_el8.6.0+2741+01592ae8

almalinux advisories ALSA-2020:4743

  • libecap Rocky Linux 8 1.0.1-2.module+el8.4.0+404+316a0dc5

rocky linux advisories RLSA-2020:4743

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-2019-12524 updated cvss 5.3

squid: Improper access restriction in url_regex may lead to security bypass

  • Red Hat Enterprise Linux 5 squid Red Hat Enterprise Linux 6 squid, squid34
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 squid, squid-sysvinit, squid-migration-script
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 8) squid 4.11-3.module+el8.3.0+7851+7808b5f9, libecap 1.0.1-2.module+el8.1.0+4044+36416a77
    fixed: vendor fix RHSA-2020:4743

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

Exploit prediction

3.86% 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
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality

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.