T05 · Unauthorized Access and Privilege Escalation
- Location
SKILL.md:10- Finding
Excessive File-Access and Command-Execution Permissions
- Content
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Vulnerability Details
File Location:
SKILL.md, lines 10-12
Vulnerability Type: Excessive Agent tool privileges
Risk Level: MediumThe skill declares general-purpose local file-reading and command-execution capabilities:
yaml tools: - read - execRelated instructions reinforce the intended availability of these capabilities at
SKILL.md:290-292:markdown - **File processing**: Supports reading, parsing, and writing multiple file formats - **API integration**: Calls external services through standardized interfaces and processes responses - **Command execution**: Executes system commands in a secure sandbox and collects resultsTechnical Analysis
The stated purpose of this skill is to search, filter, deduplicate, and summarize news. That workflow does not inherently require unrestricted access to local files or a general command-execution interface. Declaring
readandexectherefore violates the principle of least privilege.The document does not define:
- An allowlist of permitted commands or executables
- Validation or escaping rules for command arguments
- Restrictions on accessible file paths
- A restricted working directory
- Controls preventing access to environment variables or credentials
- Enforced sandbox boundaries
- A requirement for user confirmation before sensitive operations
Although the document states that commands execute in a sandbox, it provides no enforceable sandbox configuration. It also inconsistently describes the skill as
MD+EXECat line 62 and as a pure Markdown skill at line 332. No malicious command or direct exploitation implementation was found, but the excessive permissions create an exploitable capability boundary if attacker-controlled instructions reach the Agent.Attack Path
A plausible exploitation sequence is:
- A user supplies malicious input, a custom news-source URL, or content containing adversarial ins ...[truncated 1543 chars]
- Remediation
View remediation
Remediation Suggestions
- Remove
readandexecfrom the declared tools because they are not required for news aggregation. - Replace them with narrowly scoped web-search and HTTP-fetch capabilities restricted to approved protocols and domains.
- If local reading is genuinely required, limit access to a dedicated working directory and reject absolute paths, traversal sequences, symbolic-link escapes, and sensitive system locations.
- If command execution is unavoidable:
- Use a fixed executable and subcommand allowlist.
- Pass validated arguments without invoking a shell.
- Reject shell metacharacters and user-controlled command fragments.
- Run commands in an isolated container with a read-only filesystem, no host mounts, no secrets, minimal environment variables, restricted networking, and an unprivileged account.
- Require explicit user confirmation for every command.
- Treat article text, search results, custom source URLs, and callback-related values as untrusted data rather than Agent instructions.
- Document and enforce output controls that prevent local file contents or credentials from being included in news summaries.
- Correct the contradictory
MD+EXECand pure-Markdown classifications so the declared capability model accurately reflects the implementation.
- Remove