CVE-2022-23959

A flaw was found in Varnish. This flaw allows an attacker to carry out a request smuggling attack on HTTP/1 connections on Varnish cache servers. This smuggled request goes through the usual Varnish Configuration Language (VCL) processing since the Varnish server treats it as an additional request.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

This issue can be mitigated by ensuring that the Varnish server does not allow connection reuse on HTTP/1 client connections once a request body has been seen on the connection. This requires changes in the VCL configuration.