T05 · Unauthorized Access and Privilege Escalation
- Location
SKILL.md:14- Finding
Unrestricted Shell Permission Exceeds Functional Requirements
- Content
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Vulnerability Details
File Location:
SKILL.md, line 14
Vulnerability Type: Excessive tool permissions and violation of least privilege
Risk Level: MediumComplete Code Snippet:
yaml allowed-tools: Bash(*) Fetch(*)Technical Analysis
The
Bash(*)declaration permits unrestricted shell command execution. The documented workflow only needs to retrieve the Wikitólica sitemap and article pages over HTTPS, as shown by the direct HTTP method in lines 32–37. Those operations can be implemented with a narrowly scoped fetch capability, so arbitrary shell access is unnecessary.Unrestricted Bash access expands the Skill's authority from web retrieval to the full permissions of the Agent process. Commands could inspect or modify local files, invoke installed programs, access environment variables, and connect to unrelated resources. Although the audited Skill does not explicitly instruct the Agent to misuse Bash, the broad permission creates a dangerous execution channel if the Agent is influenced by malicious user input or adversarial remote content.
Attack Path
- The Skill is activated for a Catholic-related query.
- The Agent loads the Skill and receives unrestricted
Bash(*)access. - An attacker supplies crafted input, or compromised remote content contains instructions that influence subsequent Agent behavior.
- The Agent interprets that content as a reason to invoke Bash rather than the dedicated fetch capability.
- An arbitrary command executes with the operating-system privileges and resource access of the Agent process.
- Depending on the runtime environment, the command may read or alter accessible files, expose environment data, launch other programs, or communicate with unrelated network destinations.
Impact Assessment
Successful exploitation could provide command execution under the Agent process's account. The precise scope depends on sandboxing and host permissions, ...[truncated 518 chars]
- Remediation
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Remediation Suggestions
- Remove
Bash(*)and use a dedicated HTTP retrieval tool for the documented sitemap and article requests. - Restrict network access to HTTPS requests whose normalized hostname is exactly
www.wikitolica.com. - Permit only the required paths, such as
/sitemap.xmland validated article paths matching/{initial}/{slug}/. - Reject redirects to other hosts and validate the final destination after every redirect.
- Treat fetched content as untrusted data and prohibit it from authorizing tool calls or changing Agent instructions.
- If shell access is operationally unavoidable, replace
Bash(*)with a narrowly allowlisted command wrapper that accepts no shell metacharacters, validates all URL components, and invokes the HTTP client without shell interpolation. - Apply runtime sandboxing, filesystem restrictions, environment-variable isolation, and outbound network controls as defense in depth.
- Remove