📌 이 취약점에 대해 확인된 사실
전부 발행처가 발표한 값입니다. 우리가 계산하거나 판단한 숫자는 하나도 없습니다.
악용 여부
심각도 (발행처 발표값)
악용 확률 (EPSS)
0.1%
📄 원문 그대로
아래 문장은 전부 발행처가 쓴 것입니다. 번역하지 않습니다 — 보안 문서의 오역은 조치를 바꿉니다.
취약점 설명 (NVD)
A Kafka broker that authenticates clients with SASL/OAUTHBEARER using the bundled JWKS-backed validator always verifies the JWT signature, but two further checks are only performed when explicitly configured: - The issuer (iss) claim is verified only when sasl.oauthbearer.expected.issuer is set. When it is unset, a validly-signed token carrying the expected audience is accepted regardless of which issuer minted it. - An audience (aud) claim is required only when sasl.oauthbearer.expected.audience is set. When it is unset, a validly-signed token that omits the aud claim is accepted. (A token that carries an aud claim is still rejected when no expected audience is configured.) Both options default to unset and have been documented as optional (Importance LOW) since KIP-768 (3.1.0). Impact: The exposure is realizable mainly in deployments whose JWKS endpoint serves signing keys for more than one issuer (a multi-tenant identity provider, an aggregated/shared JWKS, or shared signing keys): a token minted for a different issuer, or a token lacking an audience, may be accepted to authenticate — potentially as a higher-privileged principal. In a single-issuer deployment where the provider controls the iss claim and issues audience-scoped tokens, exposure is limited. The signature trust anchor remains enforced in all cases. This is distinct from CVE-2026-33557 (acceptance of unsigned/unvalidated tokens); here the signature is validated and only the issuer/audience checks are not enforced by default. Mitigation (all affected versions, no upgrade required): Set both sasl.oauthbearer.expected.issuer (to your provider's exact iss value) and sasl.oauthbearer.expected.audience (to the audience(s) your brokers expect), per listener. Brokers that set these perform exact-match issuer/audience checks and are not affected. Both have been available since 3.1.0. Resolution: - From Apache Kafka 4.4.0: a broker configured with a JWKS endpoint fails to start unless both sasl.oauthbearer.expected.issuer and sasl.oauthbearer.expected.audience are set (secure by default). Deployments that intentionally do not restrict the issuer and/or audience may opt out per axis with sasl.oauthbearer.allow.unverified.issuer=true and/or sasl.oauthbearer.allow.unverified.audience=true.
참고
악용 확률 변화
우리가 매일 저장한 EPSS 스냅샷입니다. 원본은 전날 값만 주므로, 이 표는 수집을 시작한 이후만 보여줍니다.
| 기준일 | 확률 | 백분위 |
|---|---|---|
| 2026-11-03 | 0.12% | 2.1% |
| 2026-11-02 | 0.12% | 2.0% |
| 2026-11-01 | 0.12% | 2.1% |
| 2026-10-31 | 0.12% | 2.1% |
| 2026-10-30 | 0.12% | 2.1% |
| 2026-10-29 | 0.12% | 2.1% |
🧩 같은 약점 유형 — CWE-345
같은 분류의 다른 취약점입니다. 같은 실수가 제품을 가리지 않고 반복됩니다.