T05 · Unauthorized Access and Privilege Escalation
- Location
tests/e2e_check.py:68- Finding
Authorization Record Is Not Bound to the Requested Data File
- Content
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Vulnerability Details
File Location:
tests/e2e_check.py:68-79
Vulnerability Type: T05: Unauthorized Access and Privilege Escalation
Risk Level: MediumVulnerable Code
python if args.data: data_path = os.path.abspath(args.data) # Prevent unauthorized use: real data must not reside inside the skill directory if os.path.commonpath([data_path, SKILL_DIR]) == SKILL_DIR: print("Security block: the data path is inside the skill directory") sys.exit(1) auth_path = os.path.abspath(args.auth) if args.auth else data_path + ".auth" if not os.path.exists(auth_path): print(f"Authorization record not found: {auth_path}") sys.exit(1) with open(auth_path, encoding="utf-8") as f: auth = json.load(f) print(f"Authorization loaded: owner={auth.get('owner')} granted_by={auth.get('granted_by')}")Technical Analysis
The authorization check verifies only that the supplied authorization file exists and contains valid JSON. It does not verify that:
- The authorization record's
data_pathmatches the file supplied through--data. granted_byindicates explicit user consent.- The authorization applies to schema version 4.
- The authorization owner is associated with the selected data file.
- The authorization is current or unrevoked.
- The authorized file has not been replaced since consent was granted.
The optional
--authargument makes the weakness directly exploitable because an authorization record created for one data file can be supplied while requesting access to a different file. This contradicts the documented design that treats the authorization record as the sole permission to read a specific real-data file.Although the selected source file is copied rather than modified, copying and processing it still constitutes access. Temporary-copy isolation does not correct the missing authorization binding.
At
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- The authorization record's
- Remediation
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Remediation Suggestions
- Resolve both the requested and authorized data paths with
os.path.realpath. - Require the authorization record to follow a strict schema.
- Verify that the canonical
auth["data_path"]exactly equals the canonical--datapath. - Require
granted_byto equalexplicit-user-consent. - Require
schema_versionto equal the supported version. - Reject missing, malformed, unknown, or incorrectly typed authorization fields.
- Consider recording the authorized file's SHA-256 digest so consent cannot silently transfer to a replacement file at the same path.
- Add an expiration or revocation identifier where authorization is intended to be temporary.
- Restrict custom authorization files to an explicitly approved directory or remove
--authif cross-path authorization is unnecessary. - Add negative tests proving that an authorization record for file A cannot authorize file B, including symlink and relative-path cases.
- Resolve both the requested and authorized data paths with