{"id":"CVE-2021-41131","aliases":["GHSA-wjw6-2cqr-j4qr","PYSEC-2021-376"],"title":"Client metadata path-traversal","summary":"Client metadata path-traversal","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N","vendor":"tuf","product":"tuf","ecosystem":"pip","affected":["tuf < 0.19.0"],"patched":["tuf 0.19.0"],"published":"2021-10-19","updated":"2026-07-08","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-wjw6-2cqr-j4qr","references":[{"url":"https://github.com/theupdateframework/python-tuf/security/advisories/GHSA-wjw6-2cqr-j4qr"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-41131"},{"url":"https://github.com/theupdateframework/python-tuf/issues/1527"},{"url":"https://github.com/theupdateframework/python-tuf/commit/4ad7ae48fda594b640139c3b7eae21ed5155a102"},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/tuf/PYSEC-2021-376.yaml"},{"url":"https://github.com/theupdateframework/python-tuf"}],"tags":["osv","pip"],"epss":0.0145,"epssPercentile":0.72219,"ingestedAt":"2026-07-08T18:25:53.841Z","slug":"CVE-2021-41131","body":"## Overview\n\n### Impact\nIn both clients (`tuf/client` and `tuf/ngclient`), there is a path traversal vulnerability that in the worst case can overwrite files ending in `.json` anywhere on the client system on a call to `get_one_valid_targetinfo()`. It occurs because the rolename is used to form the filename, and may contain path traversal characters (ie `../../name.json`).\n\nThe impact is mitigated by a few facts:\n* It only affects implementations that allow arbitrary rolename selection for delegated targets metadata\n* The attack requires the ability to A) insert new metadata for the path-traversing role and B) get the role delegated by an existing targets metadata\n* The written file content is heavily restricted since it needs to be a valid, signed targets file. The file extension is always .json.\n\n### Patches\nA fix is available in version 0.19 or newer.\n\n### Workarounds\nNone that do not require code changes. Clients can restrict the allowed character set for rolenames, or they can store metadata in files named in a way that is not vulnerable: neither of these approaches is possible without modifying python-tuf.\n\n### References\n- [The issue where this was discovered](https://github.com/theupdateframework/python-tuf/issues/1527)\n- [Proof of Concept demonstrating the flaw](https://github.com/jku/path-traversal-poc)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [python-tuf](https://github.com/theupdateframework/python-tuf/issues)\n* Contact the maintainers by email or Slack\n\n\n## Affected packages\n\n- `tuf < 0.19.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `tuf 0.19.0`","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":41.3,"likelihood":0.3,"exploitation":0,"ransomware":0},"changes":[]}