CVE-2021-36371
low-risk
Published 2021-07-09
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.)
Do I need to act?
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0.10% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
3
CVSS 3.7/10
Low
NETWORK
/ HIGH complexity
Affected Products (1)
Emissary-Ingress
Affected Vendors
References (4)
18
/ 100
low-risk
Severity
13/34 · Low
Exploitability
0/34 · Minimal
Exposure
5/34 · Minimal