T09 · Insecure Skill Coding Practices
- Location
scripts/verify_action.md:113- Finding
Unrestricted Local File Read and Content Disclosure in Action Validator
- Content
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Vulnerability Details
File Location:
scripts/verify_action.md, lines 113-116 and 178
Duplicate Location:untitled folder/AI Engineering Operating System (The Unified Architecture).md, lines 393-396 and 458
Vulnerability Type: Arbitrary local-file read, sensitive-content disclosure, and validation bypass
Risk Level: MediumVulnerable Code
python def verify_content(file_path: str, expected_content: str) -> dict: """Check 2: Does the file contain the expected content?""" if not os.path.isfile(file_path): return { "check": "content_match", "passed": False, "detail": "Cannot verify content — file does not exist" } try: with open(file_path, "r", encoding="utf-8") as f: actual = f.read() match = expected_content.strip() in actual tail_lines = actual.strip().split("\n")[-3:] return { "check": "content_match", "passed": match, "tail_3_lines": tail_lines, "detail": "Content verified" if match else "CONTENT MISMATCH — agent may have written wrong data" }python parser.add_argument( "--path", required=True, help="File path the agent claims to have written" ) parser.add_argument( "--expected", required=True, help="Expected content substring" )Technical Analysis
The intended validator accepts an arbitrary path through
--pathand performs no canonicalization, approved-directory restriction, artifact ownership check, symlink rejection, or file-size limit. It consequently opens any text file readable by the process and loads the complete file into memory.The report unconditionally places the final three lines of the selected file into the
tail_3_linesfield, even when the expected-content check fails. If validator output is returned to an agent, user, or centralized log, this behavior creates a local-file disclosure primitive.The con ...[truncated 2521 chars]
- Remediation
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Remediation Suggestions
- Constrain verification to an approved output root
- Configure the allowed workspace explicitly.
- Resolve both the workspace and requested path with canonical path handling.
- Reject any path that escapes the approved directory.
python from pathlib import Path OUTPUT_ROOT = Path("/approved/output/root").resolve() def resolve_allowed_path(raw_path: str) -> Path: candidate = Path(raw_path).resolve(strict=True) if candidate != OUTPUT_ROOT and OUTPUT_ROOT not in candidate.parents: raise ValueError("Path is outside the approved output directory") return candidate-
Bind verification to the current action
- Maintain a trusted manifest of files created or modified by the current operation.
- Reject paths absent from that manifest.
- Record a pre-action file identity or hash and compare it with the post-action state rather than relying only on modification time.
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Reject unsafe expected values
- Reject empty or whitespace-only
--expectedvalues. - Prefer an exact expected digest or schema validation over a weak substring test.
- Reject empty or whitespace-only
python expected = expected_content.strip() if not expected: raise ValueError("Expected content must not be empty")-
Prevent content disclosure
- Do not include file tails or arbitrary content in normal reports.
- Return only a Boolean result, digest, byte count, or redacted diagnostic.
- If previews are necessary, require explicit authorization and redact secrets before logging.
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Limit resource consumption
- Enforce a maximum file size before reading.
- Stream bounded chunks or calculate a digest incrementally rather than loading the complete file into memory.
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Harden filesystem handling
- Reject symbolic links where possible.
- Open files defensively and verify their identity after opening to reduce time-of-check/time-of-use risks.
- Run the validator with least-privilege filesystem permission ...[truncated 434 chars]
- Constrain verification to an approved output root