CVE-2021-28116

Name: CVE-2021-28116
Creator: NVD / NIST
Published: 2021-03-09T22:15:12.88+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 13.00%

Last modified Jun 17, 2026

CVE-2021-28116 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Squid through 4.14 and 5.x through 5.0.5, in some configurations, allows information disclosure because of an out-of-bounds read in WCCP protocol data. This can be leveraged as part of a chain for remote code execution as nobody.. EPSS estimates a 13.00% chance of exploitation in the next 30 days.

Description

Squid through 4.14 and 5.x through 5.0.5, in some configurations, allows information disclosure because of an out-of-bounds read in WCCP protocol data. This can be leveraged as part of a chain for remote code execution as nobody.

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

13.00%

95.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-125

Affected Software

Vendor	Product	Versions
Squid-Cache	Squid	<= 4.14
Squid-Cache	Squid	>= 5.0, <= 5.0.5
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0

References

http://www.openwall.com/lists/oss-security/2021/10/04/1Mailing List, Third Party Advisory
http://www.squid-cache.org/Versions/Product, Vendor Advisory
https://github.com/squid-cache/squid/security/advisories/GHSA-rgf3-9v3p-qp82Broken Link
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2VCS6K3TKCF/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBTQHPBR6H66/
https://security.gentoo.org/glsa/202105-14Third Party Advisory
https://www.debian.org/security/2022/dsa-5171Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-157/Third Party Advisory, VDB Entry
http://www.openwall.com/lists/oss-security/2021/10/04/1Mailing List, Third Party Advisory
http://www.squid-cache.org/Versions/Product, Vendor Advisory
https://github.com/squid-cache/squid/security/advisories/GHSA-rgf3-9v3p-qp82Broken Link
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2VCS6K3TKCF/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBTQHPBR6H66/
https://security.gentoo.org/glsa/202105-14Third Party Advisory
https://www.debian.org/security/2022/dsa-5171Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-157/Third Party Advisory, VDB Entry

Timeline

Published: Mar 9, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-28116?

How severe is CVE-2021-28116?

CVE-2021-28116 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 13.00% probability of exploitation in the next 30 days.

How do I fix CVE-2021-28116?

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-2021-28116?

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

Scan your code now

Source: NVD / NIST