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Fencer Vulns
high 8.8

CVE-2019-12527 in the critical feed json

An issue was discovered in Squid 4.0.23 through 4.7.

published 2019-07-11 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-4122

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
50.3%
EPSS 50.3% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

An issue was discovered in Squid 4.0.23 through 4.7. When checking Basic Authentication with HttpHeader::getAuth, Squid uses a global buffer to store the decoded data. Squid does not check that the decoded length isn't greater than the buffer, leading to a heap-based buffer overflow with user controlled data.

Patch / fix

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

debian advisories DEBIAN-CVE-2019-12527

  • squid RHEL 8 7:4.4-5.module+el8.0.0+4045+70edde92
  • libecap RHEL 8 1.0.1-2.module+el8.0.0+4045+70edde92

red hat advisories RHSA-2019:2593

  • squid SLE Module for Server Applications 15 SP1, SLE Module for Server Applications 15 4.9-5.11.1

suse advisories SUSE-SU-2019:2975-1

  • squid openSUSE Tumbleweed 4.16-1.5
  • squid openSUSE Leap 15.1 4.9-lp151.2.7.1
  • squid openSUSE Leap 15.0 4.9-lp150.13.1

opensuse advisories openSUSE-SU-2024:11403-1openSUSE-SU-2019:2541-1openSUSE-SU-2019:2540-1

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

almalinux advisories ALSA-2019:2593

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

rocky linux advisories RLSA-2019:2593

  • squid Arch Linux 4.8-1

arch linux advisories AVG-1004

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-2019-12527 updated cvss 7.5

squid: heap-based buffer overflow in HttpHeader::getAuth

  • Red Hat Enterprise Linux AppStream (v. 8) squid 4.4-5.module+el8.0.0+4045+70edde92, libecap 1.0.1-2.module+el8.0.0+4045+70edde92
    fixed: vendor fix “Deny ftp:// protocol URLs being proxied and Cache Manager report access to all clients: acl FTP proto FTP http_access deny FTP http_access deny manager” RHSA-2019:2593
  • Red Hat Enterprise Linux 5 squid Red Hat Enterprise Linux 6 squid, squid34 Red Hat Enterprise Linux 7 squid, squid-sysvinit, squid-migration-script
    not affected: vulnerable code not present

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

50.30% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

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.