{"id":"GHSA-hqxw-mm44-gc4r","summary":"Istio Fragments in Path May Lead to Authorization Policy Bypass","details":"### Impact\nIstio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with `#fragment` in the path may bypass Istio’s URI path based authorization policies. \n\n### Patches\n* Istio 1.11.1 and above\n* Istio 1.10.4 and above\n* Istio 1.9.8 and above\n\n### Workarounds\nA Lua filter may be written to normalize the path.  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.\n\n### References\nMore details can be found in the [Istio Security Bulletin](https://istio.io/latest/news/security/istio-security-2021-008)\n\n### For more information\nIf you have any questions or comments about this advisory, please email us at istio-security-vulnerability-reports@googlegroups.com\n","aliases":["CVE-2021-39156"],"modified":"2026-07-17T21:12:54.868049226Z","published":"2021-08-30T16:16:14Z","database_specific":{"github_reviewed_at":"2021-08-25T22:28:17Z","nvd_published_at":"2021-08-24T23:15:00Z","cwe_ids":["CWE-706","CWE-863"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-39156"},{"type":"PACKAGE","url":"https://github.com/istio/istio"},{"type":"WEB","url":"https://istio.io/latest/news/security/istio-security-2021-008"}],"affected":[{"package":{"name":"istio.io/istio","ecosystem":"Go","purl":"pkg:golang/istio.io/istio"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.9.8"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/08/GHSA-hqxw-mm44-gc4r/GHSA-hqxw-mm44-gc4r.json"}},{"package":{"name":"istio.io/istio","ecosystem":"Go","purl":"pkg:golang/istio.io/istio"},"ranges":[{"type":"SEMVER","events":[{"introduced":"1.10.0"},{"fixed":"1.10.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/08/GHSA-hqxw-mm44-gc4r/GHSA-hqxw-mm44-gc4r.json"}},{"package":{"name":"istio.io/istio","ecosystem":"Go","purl":"pkg:golang/istio.io/istio"},"ranges":[{"type":"SEMVER","events":[{"introduced":"1.11.0"},{"fixed":"1.11.1"}]}],"versions":["1.11.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/08/GHSA-hqxw-mm44-gc4r/GHSA-hqxw-mm44-gc4r.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N"}]}