CVE-2019-12525

An issue was discovered in Squid 3.3.9 through 3.5.28 and 4.x through 4.7. When Squid is configured to use Digest authentication, it parses the header Proxy-Authorization. It searches for certain tokens such as domain, uri, and qop. Squid checks if this token's value starts with a quote and ends with one. If so, it performs a memcpy of its length minus 2. Squid never checks whether the value is just a single quote (which would satisfy its requirements), leading to a memcpy of its length minus 1.

Published: 2019-07-11 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-12525 is rated High Risk (73.2/100): CVSS Critical severity, with high exploitation likelihood (EPSS 54.55%, 98th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-12525

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-28 54.85% 54.55% -0.30%
2 2026-04-26 55.25% 54.85% -0.40%
3 2026-03-04 — 55.25% —

Full EPSS history (53 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-12525

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2019-12525

OS Trackers for CVE-2019-12525

vendor priority summary link
alpine critical CVE-2019-12525: 1 source package rows (squid); 6 state rows across 6 repos (3.10-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 1, open 5. https://security.alpinelinux.org/vuln/CVE-2019-12525
debian not yet assigned CVE-2019-12525 not yet assigned priority: Debian including 1 source packages (squid), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-12525
redhat medium — https://access.redhat.com/security/cve/CVE-2019-12525
suse high — https://www.suse.com/security/cve/CVE-2019-12525/
ubuntu medium CVE-2019-12525 medium priority: Ubuntu including 2 source packages (squid, squid3), 12 status rows across 6 suites (bionic, cosmic, disco, trusty, upstream, xenial): DNE 6, released 4, ignored 1, needed 1. https://ubuntu.com/security/CVE-2019-12525

Affected software / configurations for CVE-2019-12525

Vendor Product Version Raw CPE
squid-cache squid >= 3.3.9, <= 3.5.28 cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*
squid-cache squid >= 4.0, <= 4.7 cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
opensuse leap 15.0 cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
fedoraproject fedora 29 cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:-:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 19.04 cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:*

References for CVE-2019-12525

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00053.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00056.html Mailing List Third Party Advisory
http://www.squid-cache.org/Versions/v4/changesets/ Vendor Advisory
http://www.squid-cache.org/Versions/v4/changesets/squid-4-7f73e9c5d17664b882ed32590e6af310c247f320.patch Patch Vendor Advisory
https://github.com/squid-cache/squid/commits/v4 Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/07/msg00018.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPXN2CLAGN5QSQBTOV5IGVLDOQSRFNTZ/
https://seclists.org/bugtraq/2019/Aug/42 Mailing List Third Party Advisory
https://usn.ubuntu.com/4065-1/ Third Party Advisory
https://usn.ubuntu.com/4065-2/ Third Party Advisory
https://www.debian.org/security/2019/dsa-4507 Third Party Advisory
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