Security audit

Jj Mailbox

Security checks for vulnerabilities and agentic risk

Overview

The skill is mostly a disclosed file-based messaging tool, but its bundled script can be steered to read, write, or move files outside the declared mailbox folder through unvalidated agent names.

Review before installing. Use only with trusted mailbox repos and trusted agent names, avoid running it on sensitive directories, and prefer a fixed version that validates agent identifiers and rejects traversal, absolute paths, and symlink escapes before reading or writing files.

A.I.G

Vulnerability Patterns

Unauthorized Access and Privilege EscalationObtains permissions beyond the task's legitimate needs
Skill Instruction HijackingAlters the agent's session goals or safety constraints when the skill loads
Agent Memory PoisoningWrites attacker-controlled rules into memory that affect later sessions
Remote Payload Retrieval and ExecutionFetches external code whose behavior can change after review
Embedded Malicious CodeShips malicious scripts inside the skill and executes them locally

Findings (1)

T05 · Unauthorized Access and Privilege Escalation

Error

Location: jj-mailbox.sh:139
Finding: Path Traversal Allows File Access Outside the Mailbox Repository
Content: View full analysis
}" local desc="${2:-Agent ${name}}" local repo repo="$(get_repo)" cd "${repo}" # Create agent directories mkdir -p "agents/${name}" "inbox/${name}/new" "inbox/${name}/processed" # Write profile cat > "agents/${name}/profile.json" </dev/null || echo " (none)" exit 1 fi local msg_id="msg-$(gen_id)" local ts ts="$(ts_filename)" local filename="${ts}_${from}_${msg_id}.json" # Buil ...[truncated 4744 chars]
Remediation: View remediation

SkillSpector

Vulnerability Patterns

Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep