CVE-2021-36740: Medium severity Varnish-cache Varnish Cache vulnerability
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/varnishto a version that resolves this vulnerability.Fixed in 7.1.1-2+deb12u1Fixed in 7.7.0-3+deb13u1Fixed in 7.7.0-3+deb13u2 - Upgrade
Upgrade
Varnish Enterpriseto a version that resolves this vulnerability.Fixed in 6.0.8r3 - Upgrade
Upgrade
Varnish Cacheto a version that resolves this vulnerability.Fixed in 6.5.2 - Upgrade
Upgrade
Varnish Cacheto a version that resolves this vulnerability.Fixed in 6.6.1 - Upgrade
Upgrade
Varnish Cacheto a version that resolves this vulnerability.Fixed in 6.0.8
Event History
Frequently Asked Questions
What is the vulnerability ID for this vulnerability?
The vulnerability ID is CVE-2021-36740.
What is the severity of CVE-2021-36740?
The severity of CVE-2021-36740 is medium (6.5).
Which software versions are affected by CVE-2021-36740?
Varnish Enterprise 6.0.x before 6.0.8r3, 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 are affected by CVE-2021-36740.
How can I fix CVE-2021-36740?
To fix CVE-2021-36740, you should update Varnish Cache to version 6.5.2, 6.6.1, or 6.0.8, depending on the software version you are using.
Where can I find more information about CVE-2021-36740?
You can find more information about CVE-2021-36740 on the Varnish Software website and the GitHub page of Varnish Cache.