CVE-2020-15810

An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Smuggling attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows any client, including browser scripts, to bypass local security and poison the proxy cache and any downstream caches with content from an arbitrary source. When configured for relaxed header parsing (the default), Squid relays headers containing whitespace characters to upstream servers. When this occurs as a prefix to a Content-Length header, the frame length specified will be ignored by Squid (allowing for a conflicting length to be used from another Content-Length header) but relayed upstream.

• CWE-444

• http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00012.htmlMailing List, Third Party Advisory
• http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00017.htmlMailing List, Third Party Advisory
• https://github.com/squid-cache/squid/security/advisories/GHSA-3365-q9qx-f98mMitigation, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2020/10/msg00005.htmlMailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BE6FKUN7IGTIR2MEEMWYDT7N5EJJLZI2/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BMTFLVB7GLRF2CKGFPZ4G4R5DIIPHWI3/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HJJDI7JQFGQLVNCKMVY64LAFMKERAOK7/
• https://security.netapp.com/advisory/ntap-20210219-0007/Third Party Advisory
• https://security.netapp.com/advisory/ntap-20210226-0006/Third Party Advisory
• https://security.netapp.com/advisory/ntap-20210226-0007/Broken Link
• https://usn.ubuntu.com/4477-1/Third Party Advisory
• https://usn.ubuntu.com/4551-1/Third Party Advisory
• https://www.debian.org/security/2020/dsa-4751Third Party Advisory
• http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00012.htmlMailing List, Third Party Advisory
• http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00017.htmlMailing List, Third Party Advisory
• https://github.com/squid-cache/squid/security/advisories/GHSA-3365-q9qx-f98mMitigation, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2020/10/msg00005.htmlMailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BE6FKUN7IGTIR2MEEMWYDT7N5EJJLZI2/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BMTFLVB7GLRF2CKGFPZ4G4R5DIIPHWI3/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HJJDI7JQFGQLVNCKMVY64LAFMKERAOK7/
• https://security.netapp.com/advisory/ntap-20210219-0007/Third Party Advisory
• https://security.netapp.com/advisory/ntap-20210226-0006/Third Party Advisory
• https://security.netapp.com/advisory/ntap-20210226-0007/Broken Link
• https://usn.ubuntu.com/4477-1/Third Party Advisory
• https://usn.ubuntu.com/4551-1/Third Party Advisory
• https://www.debian.org/security/2020/dsa-4751Third Party Advisory

Published

Sep 2, 2020

Last Modified

Jun 17, 2026

Status

Modified

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