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Vulnerability record · CVE-2021-28116 · published 9 March 2021

CVE-2021-28116: Squid-cache squid out-of-bounds read vulnerability

Squid Cache · Squid

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.

5.3 CVSS 3.1 Medium EPSS 13% · top 3.8% CWE-125 · Out-of-bounds read
5.3CVSS 3.1 base score, v2 4.3
13%EPSS exploitation probability, 30 days
NoNot in CISA KEV
3Affected product versions listed by NVD
16References
17 Jun 2026Last modified by NVD

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.

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

Affected products

3 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.openwall.com/lists/oss-security/2021/10/04/1 Mailing ListThird Party Advisory
http://www.squid-cache.org/Versions/ ProductVendor Advisory
https://github.com/squid-cache/squid/security/advisories/GHSA-rgf3-9v3p-qp82 Broken Link
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2V
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBT
https://security.gentoo.org/glsa/202105-14 Third Party Advisory
https://www.debian.org/security/2022/dsa-5171 Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-157/ Third Party AdvisoryVDB Entry
http://www.openwall.com/lists/oss-security/2021/10/04/1 Mailing ListThird Party Advisory
http://www.squid-cache.org/Versions/ ProductVendor Advisory
https://github.com/squid-cache/squid/security/advisories/GHSA-rgf3-9v3p-qp82 Broken Link
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2V
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBT
https://security.gentoo.org/glsa/202105-14 Third Party Advisory
https://www.debian.org/security/2022/dsa-5171 Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-157/ Third Party AdvisoryVDB Entry

Track CVE-2021-28116 inside VULONE

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Source: NIST National Vulnerability Database (record CVE-2021-28116), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.