| Name | CVE-2021-36740 |
| Description | 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-5088-1 |
| Debian Bugs | 991040 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| varnish (PTS) | jessie, jessie (lts) | 4.0.2-1+deb8u1 | fixed |
| stretch (security), stretch (lts), stretch | 5.0.0-7+deb9u3 | vulnerable | |
| buster | 6.1.1-1+deb10u3 | fixed | |
| buster (security) | 6.1.1-1+deb10u4 | fixed | |
| bullseye (security), bullseye | 6.5.1-1+deb11u3 | fixed | |
| bookworm | 7.1.1-1.1 | fixed | |
| sid, trixie | 7.1.1-1.2 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| varnish | source | jessie | (not affected) | |||
| varnish | source | buster | 6.1.1-1+deb10u3 | DSA-5088-1 | ||
| varnish | source | bullseye | 6.5.1-1+deb11u2 | DSA-5088-1 | ||
| varnish | source | (unstable) | 6.5.2-1 | 991040 |
[stretch] - varnish <ignored> (HTTP/2 support is marked experimental in 5.0 and enabling is not recommended, code is quite different)
https://varnish-cache.org/security/VSV00007.html
https://github.com/varnishcache/varnish-cache/commit/9be22198e258d0e7a5c41f4291792214a29405cf (6.0.8)
https://github.com/varnishcache/varnish-cache/commit/82b0a629f60136e76112c6f2c6372cce77b683be (6.5.2)
[jessie] - varnish <not-affected> (HTTP/2 support added in 5.0)