CVE-2021-39155
Authorization Policy Bypass Due to Case Insensitive Host Comparison
描述
### Impact According to [RFC 4343](https://datatracker.ietf.org/doc/html/rfc4343), Istio authorization policy should compare the hostname in the HTTP Host header in a case insensitive way, but currently the comparison is case sensitive. The Envoy proxy will route the request hostname in a case-insensitive way which means the authorization policy could be bypassed. As an example, the user may have an authorization policy that rejects request with hostname "httpbin.foo" for some source IPs, but the attacker can bypass this by sending the request with hostname "Httpbin.Foo". ### Patches * Istio 1.11.1 and above * Istio 1.10.4 and above * Istio 1.9.8 and above ### Workarounds A Lua filter may be written to normalize Host header before the authorization check. This is similar to the Path normalization presented in the [Security Best Practices](https://istio.io/latest/docs/ops/best-practices/security/#case-normalization) guide. ### References More details can be found in the [Istio Security Bulletin](https://istio.io/latest/news/security/istio-security-2021-008). ### For more information If you have any questions or comments about this advisory, please email us at istio-security-vulnerability-reports@googlegroups.com
如何修補 CVE-2021-39155
要修補 CVE-2021-39155,請將受影響套件升級到下列已修補版本。
- —升級至 1.9.8 或更新版本
CVE-2021-39155 正在被利用嗎?
低 — EPSS 為 1.2%,目前沒有觀察到大規模利用活動。
受影響套件(1)
- from 0, < 1.9.8
CVSS 分數
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