Description
Varnish 3.x before 3.0.7, when used in certain stacked installations, allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via a header line terminated by a \r (carriage return) character in conjunction with multiple Content-Length headers in an HTTP request.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 13 | varnish | 4.0.0-1 | — |
| Debian 12 | varnish | 4.0.0-1 | — |
| Debian 7 | varnish | 3.0.2-2+deb7u2 | DSA-3553-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | varnish | 3.0.5-2ubuntu0.1 | — |
Advisories 1
- DSA-3553-1 varnish - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- DSA-3553 vendor-advisory
- [varnish-announce] 20150323 Varnish 3.0.7 released. mailing-list
- [oss-security] 20160418 Re: CVE request: Varnish 3 before 3.0.7 was vulnerable to HTTP Smuggling issues: Double Content Length and bad EOL mailing-list
- GLSA-201607-10 vendor-advisory
- https://github.com/varnish/Varnish-Cache/commit/29870c8fe95e4e8a672f6f28c5fbe692bea09e9c
- https://github.com/varnish/Varnish-Cache/commit/85e8468bec9416bd7e16b0d80cb820ecd2b330c3
- [oss-security] 20160416 CVE request: Varnish 3 before 3.0.7 was vulnerable to HTTP Smuggling issues: Double Content Length and bad EOL mailing-list
- openSUSE-SU-2016:1316 vendor-advisory