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.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.13%
Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory debian.org Vendor Advisory varnish-software.com Vendor Advisory varnish-cache.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://varnish-cache.org/security/VSV00007.html mitigation vendor advisory
https://docs.varnish-software.com/security/VSV00007/ mitigation vendor advisory
https://github.com/varnishcache/varnish-cache/commit/9be22198e258d0e7a5c41f4291792214a29405cf third party advisory patch
https://github.com/varnishcache/varnish-cache/commit/82b0a629f60136e76112c6f2c6372cce77b683be third party advisory patch
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZHBNLDEOTGYRIEQZBWV7F6VPYS4O2AAK/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/THV2DQA2GS65HUCKK4KSD2XLN3AAQ2V5/ vendor advisory
https://www.debian.org/security/2022/dsa-5088 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-36740?
CVE-2021-36740 has been scored as a medium severity vulnerability.
How to fix CVE-2021-36740?
To fix CVE-2021-36740, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-36740 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-36740 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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