CVE-2020-8517

Name: CVE-2020-8517
Creator: NVD / NIST
Published: 2020-02-04T20:15:14.857+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 6.85%

Last modified Jun 17, 2026

CVE-2020-8517 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. EPSS estimates a 6.85% chance of exploitation in the next 30 days.

Description

An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with memory access protections, this can result in the helper process being terminated unexpectedly. This leads to the Squid process also terminating and a denial of service for all clients using the proxy.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

6.85%

93.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Squid-Cache	Squid	< 4.10
Opensuse	Leap	15.1
Canonical	Ubuntu Linux	16.04
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	19.10

References

http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00012.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00010.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00018.htmlMailing List, Third Party Advisory
http://www.squid-cache.org/Advisories/SQUID-2020_3.txtVendor Advisory
http://www.squid-cache.org/Versions/v4/changesets/squid-4-6982f1187a26557e582172965e266f544ea562a5.patchPatch, Vendor Advisory
https://security.gentoo.org/glsa/202003-34Third Party Advisory
https://security.netapp.com/advisory/ntap-20210304-0002/Third Party Advisory
https://usn.ubuntu.com/4289-1/Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00012.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00010.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00018.htmlMailing List, Third Party Advisory
http://www.squid-cache.org/Advisories/SQUID-2020_3.txtVendor Advisory
http://www.squid-cache.org/Versions/v4/changesets/squid-4-6982f1187a26557e582172965e266f544ea562a5.patchPatch, Vendor Advisory
https://security.gentoo.org/glsa/202003-34Third Party Advisory
https://security.netapp.com/advisory/ntap-20210304-0002/Third Party Advisory
https://usn.ubuntu.com/4289-1/Third Party Advisory

Timeline

Published: Feb 4, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-8517?

How severe is CVE-2020-8517?

CVE-2020-8517 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 6.85% probability of exploitation in the next 30 days.

How do I fix CVE-2020-8517?

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-2020-8517?

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

Scan your code now

Source: NVD / NIST