CVE-2021-36740 — HTTP Request Smuggling in Varnish Cache

CWE-444 — HTTP Request Smuggling9 documents8 sources
Severity
6.5MEDIUMNVD
OSV7.5
EPSS
0.7%
top 27.77%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
6
Varnish-cache VarnishVarnish-cache Varnish CacheVarnish-software Varnish Cache+3 more
Timeline
PublishedJul 14
Latest updateJun 8

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NExploitability: 3.9 | Impact: 2.5

Affected Packages5 packages

▶NVDvarnish-cache/varnish_cache6.0.0 — 6.0.8+1
▶Debianvarnish-cache/varnish< 6.5.1-1+deb11u2+3
▶Ubuntuvarnish-cache/varnish< 5.2.1-1ubuntu0.1+2
▶NVDvarnish-software/varnish_cache6.0.0 — 6.0.5+1

Also affects: Debian Linux 10.0, 11.0, Fedora 33, 34

Patches

Patch: github.com ↗Patch: github.com ↗Patch: github.com ↗

🔴Vulnerability Details

4
OSV
varnish vulnerabilities↗2022-06-08
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GHSA
GHSA-8vxj-gx32-j925: Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request↗2022-05-24
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OSV
CVE-2021-36740: Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request↗2021-07-14
▶
CVEList
CVE-2021-36740: Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request↗2021-07-14
▶

📋Vendor Advisories

3
Ubuntu
Varnish Cache vulnerabilities↗2022-06-08
▶
Red Hat
varnish: HTTP/2 request smuggling attack via a large Content-Length header for a POST request↗2021-07-13
▶
Debian
CVE-2021-36740: varnish - Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorizati...↗2021
▶

📐Framework References

1
OWASP
VWAD: Varnish HTTP/2 Request Smuggling↗
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CVE-2021-36740 — HTTP Request Smuggling | cvebase