🔍 CVE-2026-33495

6.5
CVSS Score
MEDIUM
2026-03-26
2026-06-17 10:37
✅ 완료

🇰🇷 한글 설명

Ory Oathkeeper는 설정된 Access Rules를 평가할 때 X-Forwarded-Proto 헤더를 항상 신뢰하는 취약점이 있습니다. 이로 인해 trust_forwarded_headers 설정이 false임에도 불구하고 공격자가 헤더를 조작하여 의도하지 않은 규칙을 트리거할 수 있습니다. 26.2.0 미만 버전에서 발생하며, 해당 버전에서는 이 설정이 올바르게 적용되지 않습니다.

💡 쉬운 설명

보안 검사 도구가 사용자가 보낸 가짜 정보를 진짜라고 믿어버리는 문제입니다. 공격자가 '나는 안전한 연결(HTTPS)을 사용 중이다'라고 거짓말을 하면, 보안 규칙을 우회할 수 있습니다.

🇺🇸 원문 (English)

ORY Oathkeeper is an Identity & Access Proxy (IAP) and Access Control Decision API that authorizes HTTP requests based on sets of Access Rules. Ory Oathkeeper is often deployed behind other components like CDNs, WAFs, or reverse proxies. Depending on the setup, another component might forward the request to the Oathkeeper proxy with a different protocol (http vs. https) than the original request. In order to properly match the request against the configured rules, Oathkeeper considers the `X-Forwarded-Proto` header when evaluating rules. The configuration option `serve.proxy.trust_forwarded_headers` (defaults to false) governs whether this and other `X-Forwarded-*` headers should be trusted. Prior to version 26.2.0, Oathkeeper did not properly respect this configuration, and would always consider the `X-Forwarded-Proto` header. In order for an attacker to abuse this, an installation of Ory Oathkeeper needs to have distinct rules for HTTP and HTTPS requests. Also, the attacker needs to be able to trigger one but not the other rule. In this scenario, the attacker can send the same request but with the `X-Forwarded-Proto` header in order to trigger the other rule. We do not expect many configurations to meet these preconditions. Version 26.2.0 contains a patch. Ory Oathkeeper will correctly respect the `serve.proxy.trust_forwarded_headers` configuration going forward, thereby eliminating the attack scenario. We recommend upgrading to a fixed version even if the preconditions are not met. As an additional mitigation, it is generally recommended to drop any unexpected headers as early as possible when a request is handled, e.g. in the WAF.

📍 영향받는 시스템

Ory Oathkeeper versions prior to 26.2.0

⚔️ 공격 벡터

X-Forwarded-Proto 헤더를 조작하여 HTTP와 HTTPS에 대해 서로 다른 보안 규칙이 적용된 경우 규칙을 우회함

🛡️ 대응 방법

Ory Oathkeeper를 26.2.0 이상의 버전으로 업그레이드하고, WAF 등에서 예상치 못한 헤더를 사전에 차단합니다.

🔧 검증 코드

출력된 버전이 26.2.0 이상인지 확인하여 취약 여부를 판단합니다.

Shell / Script
ory version | grep -E '26\.[2-9]|2[7-9]\.|[3-9]\.' || echo 'Vulnerable'

📊 CVSS Vector String

CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

💻 영향받는 소프트웨어

IBM Verify Identity Access