Published: 14 July 2021
Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. This affects Varnish Enterprise 6.0.x before 6.0.8r3, and Varnish Cache 5.x and 6.x before 6.5.2, 6.6.x before 6.6.1, and 6.0 LTS before 6.0.8.
CVSS 3 base score: 6.5
Launchpad, Ubuntu, Debian
(out of standard support)
According to Debian: (HTTP/2 support is marked experimental in 5.0 and enabling is not recommended, code is quite different)
- https://github.com/varnishcache/varnish-cache/commit/9be22198e258d0e7a5c41f4291792214a29405cf (6.0.8)
- https://github.com/varnishcache/varnish-cache/commit/82b0a629f60136e76112c6f2c6372cce77b683be (6.5.2)