In Varnish Cache before 6.6.2 and 7.x before 7.0.2, Varnish Cache 6.0 LTS before 6.0.10, and and Varnish Enterprise (Cache Plus) 4.1.x before 4.1.11r6 and 6.0.x before 6.0.9r4, request smuggling can occur for HTTP/1 connections.

Affected: Ubuntu:18.04:LTS: varnish, Ubuntu:20.04:LTS: varnish, Ubuntu:22.04:LTS: varnish

It was dicovered that Varnish Cache did not clear a pointer between the handling of one client request and the next request within the same connection. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2019-20637)

It was discovered that Varnish Cache could have an assertion failure when a TLS termination proxy uses PROXY version 2. A remote attacker could possibly use this issue to restart the daemon and cause a performance loss. (CVE-2020-11653)

It was discovered that Varnish Cache allowed request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2021-36740)

It was discovered that Varnish Cache allowed request smuggling for HTTP/1 connections. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2022-23959)