CVE-2021-36371 Auth bypass in n/a
Attackers can bypass mTLS client certificate requirements on protected backends by manipulating SNI and Host headers in specific multi-TLSContext configurations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-36371?
CVE-2021-36371 is a low-severity authentication bypass vulnerability in n/a, published on 9 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.)
Weakness: CWE-295
Which versions are affected by CVE-2021-36371?
It affects 1 product.
Products include Getambassador Emissary-Ingress.
How do I fix CVE-2021-36371?
No fix has been published for CVE-2021-36371 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2021-36371 being exploited?
There is no known exploitation of CVE-2021-36371 in the wild and no public exploit code.
Sources
Also known as GHSA-hc2q-w3c3-348m.