Cyber Resilience

CVE-2021-36740

Medium

Published: 14 July 2021

Published
14 July 2021
Modified
21 November 2024
KEV Added
—
Patch
—
CVSS Score v3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS Score 0.0096 76.9th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-36740 is a medium-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Varnish-Cache Varnish Cache. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 23.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

6.0 LTS before 6.0.8.

CWE(s)
CWE-444

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

varnish-cache
varnish cache
6.0.8 · 6.0.0 — 6.0.8
varnish-software
varnish cache
6.0.0 — 6.0.5 · 6.0.0 — 6.0.7
varnish cache project
varnish cache
5.0.0 — 5.2.1 · 6.1.0 — 6.6.0
fedoraproject
fedora
33, 34
debian
debian linux
10.0, 11.0

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References