What’s Vulnerable › Vulnerabilities

CVE-2021-46784

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 5.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-07-17 · updated 2026-06-17
• Weakness: CWE-617

Description

In Squid 3.x through 3.5.28, 4.x through 4.17, and 5.x before 5.6, due to improper buffer management, a Denial of Service can occur when processing long Gopher server responses.

Affected products

• Debian Linux: 10.0, 11.0, 12.0
• Squid: from 3.0 through 3.5.28; from 4.0 through 4.17; from 5.0 before 5.6 — fixed in 5.6

How to fix

Upgrade to a fixed version: Squid 5.6. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2023/10/13/1
• http://www.openwall.com/lists/oss-security/2023/10/13/10
• http://www.openwall.com/lists/oss-security/2023/10/21/1
• http://www.squid-cache.org/Versions/v4/changesets/SQUID-2021_7.patch
• http://www.squid-cache.org/Versions/v5/changesets/SQUID-2021_7.patch
• https://github.com/squid-cache/squid/commit/5e2ea2b13bd98f53e29964ca26bb0d602a8a12b9
• https://github.com/squid-cache/squid/security/advisories/GHSA-f5cp-6rh3-284w
• https://security-tracker.debian.org/tracker/CVE-2021-46784
• https://security.netapp.com/advisory/ntap-20221223-0007/
• http://www.openwall.com/lists/oss-security/2023/10/13/1
• http://www.openwall.com/lists/oss-security/2023/10/13/10
• http://www.openwall.com/lists/oss-security/2023/10/21/1

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