CVE-2021-36371 describes a bypass vulnerability in Emissary-Ingress (formerly Ambassador API Gateway) versions through 1.13.9, allowing attackers to circumvent client certificate requirements (mTLS) on backend upstreams. This occurs when multiple TLSContexts are defined, and at least one does not require client certificate authentication. An attacker can exploit this by sending an SNI for an unprotected backend and an HTTP Host header for a protected backend. The vulnerability has a CVSS score of 3.7 (LOW), indicating a network-based attack with high attack complexity and a low impact on integrity, with no confidentiality or availability impact. It affects Emissary-Ingress versions 1.x, but not 2.x, or 1.x with specific configuration settings. Currently, there is no evidence of active exploitation, and no public exploit code (Metasploit, Nuclei, ExploitDB) or KEV catalog entry exists. Community discussion and media coverage are minimal, suggesting low public awareness and attention to this vulnerability.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
<= 1.13.9CPE matchmatch criteria | cpe:2.3:a:getambassador:emissary-ingress:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.3 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
Remediation records are not available for this CVE.