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Vulnerability record · CVE-2023-46724 · published 1 November 2023

CVE-2023-46724: Squid-cache squid out-of-bounds read vulnerability

Squid Cache · Squid

Squid is a caching proxy for the Web. Due to an Improper Validation of Specified Index bug, Squid versions 3.3.0.1 through 5.9 and 6.0 prior to 6.4 compiled using `--with-openssl` are vulnerable to a Denial of Service attack against SSL Certificate validation. This problem allows a remote server to perform Denial of Service against Squid Proxy by initiating a TLS Handshake with a specially crafted SSL Certificate in a server certificate chain. This attack is limited to HTTPS and SSL-Bump. This bug is fixed in Squid version 6.4. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives. Those who you use a prepackaged version of Squid should refer to the package vendor for availability information on updated packages.

7.5 CVSS 3.1 High EPSS 4.0% · top 9.6% CWE-125 · Out-of-bounds readCWE-129 · CWE-129
7.5CVSS 3.1 base score
4.0%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
14References
17 Jun 2026Last modified by NVD

Description

Squid is a caching proxy for the Web. Due to an Improper Validation of Specified Index bug, Squid versions 3.3.0.1 through 5.9 and 6.0 prior to 6.4 compiled using `--with-openssl` are vulnerable to a Denial of Service attack against SSL Certificate validation. This problem allows a remote server to perform Denial of Service against Squid Proxy by initiating a TLS Handshake with a specially crafted SSL Certificate in a server certificate chain. This attack is limited to HTTPS and SSL-Bump. This bug is fixed in Squid version 6.4. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives. Those who you use a prepackaged version of Squid should refer to the package vendor for availability information on updated packages.

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

Affected products

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

References

LinkTags
http://www.squid-cache.org/Versions/v5/SQUID-2023_4.patch Mailing ListPatch
http://www.squid-cache.org/Versions/v6/SQUID-2023_4.patch Mailing ListPatch
https://github.com/squid-cache/squid/commit/b70f864940225dfe69f9f653f948e787f99c3810 Patch
https://github.com/squid-cache/squid/security/advisories/GHSA-73m6-jm96-c6r3 Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/A5QASTMCUSUEW3UOMKHZJB3FT
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MEV66D3PAAY6K7TWDT3WZBLCP
https://security.netapp.com/advisory/ntap-20231208-0001/
http://www.squid-cache.org/Versions/v5/SQUID-2023_4.patch Mailing ListPatch
http://www.squid-cache.org/Versions/v6/SQUID-2023_4.patch Mailing ListPatch
https://github.com/squid-cache/squid/commit/b70f864940225dfe69f9f653f948e787f99c3810 Patch
https://github.com/squid-cache/squid/security/advisories/GHSA-73m6-jm96-c6r3 Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/A5QASTMCUSUEW3UOMKHZJB3FT
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MEV66D3PAAY6K7TWDT3WZBLCP
https://security.netapp.com/advisory/ntap-20231208-0001/

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2023-46724), CISA KEV, FIRST EPSS (scores of 2026-10-07). This page is refreshed as NVD updates the record.