CVE-2019-18679

Name: CVE-2019-18679
Creator: NVD / NIST
Published: 2019-11-26T17:15:13.047+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 40.98%

Last modified Jun 17, 2026

CVE-2019-18679 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered in Squid 2.x, 3.x, and 4.x through 4.8. Due to incorrect data management, it is vulnerable to information disclosure when processing HTTP Digest Authentication. EPSS estimates a 40.98% chance of exploitation in the next 30 days.

Description

An issue was discovered in Squid 2.x, 3.x, and 4.x through 4.8. Due to incorrect data management, it is vulnerable to information disclosure when processing HTTP Digest Authentication. Nonce tokens contain the raw byte value of a pointer that sits within heap memory allocation. This information reduces ASLR protections and may aid attackers isolating memory areas to target for remote code execution attacks.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

40.98%

98.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-200

Affected Software

Vendor	Product	Versions	Update
Squid-Cache	Squid	>= 2.0, <= 2.7	—
Squid-Cache	Squid	>= 3.0, <= 3.5.28	—
Squid-Cache	Squid	>= 4.0, <= 4.8	—
Squid-Cache	Squid	2.7	Stable2
Canonical	Ubuntu Linux	16.04	—
Canonical	Ubuntu Linux	18.04	—
Canonical	Ubuntu Linux	19.04	—
Canonical	Ubuntu Linux	19.10	—
Debian	Debian Linux	8.0	—
Fedoraproject	Fedora	30	—
Fedoraproject	Fedora	31	—

References

http://www.squid-cache.org/Advisories/SQUID-2019_11.txtThird Party Advisory
http://www.squid-cache.org/Versions/v4/changesets/squid-4-671ba97abe929156dc4c717ee52ad22fba0f7443.patchRelease Notes
https://bugzilla.suse.com/show_bug.cgi?id=1156324Issue Tracking, Third Party Advisory
https://github.com/squid-cache/squid/pull/491Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/12/msg00011.htmlThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MTM74TU2BSLT5B3H4F3UDW53672NVLMC/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UEMOYTMCCFWK5NOXSXEIH5D2VGWVXR67/
https://security.gentoo.org/glsa/202003-34
https://usn.ubuntu.com/4213-1/Third Party Advisory
https://www.debian.org/security/2020/dsa-4682
http://www.squid-cache.org/Advisories/SQUID-2019_11.txtThird Party Advisory
http://www.squid-cache.org/Versions/v4/changesets/squid-4-671ba97abe929156dc4c717ee52ad22fba0f7443.patchRelease Notes
https://bugzilla.suse.com/show_bug.cgi?id=1156324Issue Tracking, Third Party Advisory
https://github.com/squid-cache/squid/pull/491Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/12/msg00011.htmlThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MTM74TU2BSLT5B3H4F3UDW53672NVLMC/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UEMOYTMCCFWK5NOXSXEIH5D2VGWVXR67/
https://security.gentoo.org/glsa/202003-34
https://usn.ubuntu.com/4213-1/Third Party Advisory
https://www.debian.org/security/2020/dsa-4682

Timeline

Published: Nov 26, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-18679?

How severe is CVE-2019-18679?

CVE-2019-18679 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 40.98% probability of exploitation in the next 30 days.

How do I fix CVE-2019-18679?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-18679?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST