CVE-2021-36371

Public Exploit

Description

Emissary-Ingress (formerly Ambassador API Gateway) through 1.13.9 allows attackers to bypass client certificate requirements (i.e., mTLS cert_required) on backend upstreams when more than one TLSContext is defined and at least one configuration exists that does not require client certificate authentication. The attacker must send an SNI specifying an unprotected backend and an HTTP Host header specifying a protected backend. (2.x versions are unaffected. 1.x versions are unaffected with certain configuration settings involving prune_unreachable_routes and a wildcard Host resource.)

Category

3.7
CVSS
Severity: Low
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.07%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://github.com/emissary-ingress/emissary/issues/3340 third party advisory exploit
https://github.com/emissary-ingress/emissary/releases/tag/v2.0.0-ea third party advisory release notes

Frequently Asked Questions

What is the severity of CVE-2021-36371?
CVE-2021-36371 has been scored as a low severity vulnerability.
How to fix CVE-2021-36371?
To fix CVE-2021-36371, 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-2021-36371 being actively exploited in the wild?
It is possible that CVE-2021-36371 is being exploited or will be exploited in a near future based on public information. 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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