CVE intelligence and bounded remediation

CVE-2023-30845 — ESPv2 is a service proxy that provides API management capabilities using Google Service Infrastructure

Critical CVSS 9.8

ESPv2 is a service proxy that provides API management capabilities using Google Service Infrastructure. ESPv2 2.20.0 through 2.42.0 contains an authentication bypass vulnerability. API clients can craft a malicious `X-HTTP-Method-Override` header value to bypass JWT authentication in specific cases. ESPv2 allows malicious requests to bypass authentication if both the conditions are true: The requested HTTP method is **not** in the API service definition (OpenAPI spec or gRPC `google.api.http` proto annotations, and the specified `X-HTTP-Method-Override` is a valid HTTP method in the API service definition. ESPv2 will forward the request to your backend without checking the JWT. Attackers can craft requests with a malicious `X-HTTP-Method-Override` value that allows them to bypass specifying JWTs. Restricting API access with API keys works as intended and is not affected by this vulnerability. Upgrade deployments to release v2.43.0 or higher to receive a patch. This release ensures that JWT authentication occurs, even when the caller specifies `x-http-method-override`. `x-http-method-override` is still supported by v2.43.0+. API clients can continue sending this header to ESPv2.

Severity
Critical
CVSS
9.8 (3.1)
Published
2023-04-26
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-287

Affected products

  • google / espv2

Matched remediation archetype

Authentication bypass and missing authentication

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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