Pdf Batch Compress Skill

• Outcome: Review
• Latest audit: Jul 21, 2026 · 8:54 AM UTC
• Version: 1.0.0

Overview

This appears to be a real PDF compression skill, but it can permanently overwrite many PDFs with lossy lower-quality versions without backups, confirmation, or dry-run controls.

Install only if you are comfortable with irreversible, lossy in-place PDF replacement. Run it first on a copied test directory, keep backups of originals, verify whether searchable text/OCR matters for your PDFs, and avoid running it on legal, archival, financial, or only-copy documents until the skill adds dry-run, backup, and explicit overwrite controls.

SkillSpector

By NVIDIA

Vulnerability Patterns

• Output Handling: Unvalidated Output Injection, Cross-Context Output, Unbounded Output
• MCP Least Privilege: Underdeclared Capability, Wildcard Permission, Missing Permission Declaration
• Prompt Injection: Instruction Override, Hidden Instructions, Exfiltration Commands
• Data Exfiltration: External Transmission, Env Variable Harvesting, File System Enumeration
• Privilege Escalation: Excessive Permissions, Sudo/Root Execution, Credential Access

Findings (5)

Lp3

Medium

• Category: MCP Least Privilege
• Confidence: 96% confidence
• Finding: The skill clearly instructs the agent to execute shell commands (`bash`, `find`, `xargs`, `gs`, Python scripts), yet the metadata declares no permissions. That mismatch is a real security issue because it obscures the skill's operational capabilities from any permission or review layer, increasing the chance of unintended command execution without explicit user understanding or platform enforcement.

Missing User Warnings

Medium

• Confidence: 88% confidence
• Finding: The README explicitly documents a fallback mode that renders PDFs into image-based PDFs and applies multi-level DPI degradation, but it does not warn users that this can materially alter document fidelity, remove semantic/text structure, or degrade archival/legal usability. In a bulk-processing skill, omission of these warnings increases the chance of silent destructive modification at scale, especially if users assume compression is lossless or minimally invasive.

Missing User Warnings

Medium

• Confidence: 94% confidence
• Finding: The skill states that compressed files will replace the originals in place while preserving the original filename, but it does not prominently warn about irreversible quality loss, failed transformations, or the need to back up data first. In this context, the skill performs lossy PDF recompression and bulk processing, so a mistaken target path or poor compression result could destroy user data at scale.

Missing User Warnings

Medium

• Confidence: 92% confidence
• Finding: The script is explicitly designed to replace original PDF files after compression, but it provides no interactive confirmation, dry-run mode, or automatic backup before destructive changes. In a batch-processing context, this can cause irreversible data loss or quality degradation across many files if the threshold, target directory, or compression behavior is wrong.

Unvalidated Output Injection

High

• Category: Output Handling

Content

if not GS:
    # 尝试从 PATH 查找
    try:
        result = subprocess.run(["which", "gs"], capture_output=True, text=True)
        if result.returncode == 0:
            GS = result.stdout.strip()
    except Exception:

• Confidence: 78% confidence
• Finding: subprocess.run(["which", "gs"], capture_output

VirusTotal

65/65 vendors flagged this skill as clean.

Static analysis

No suspicious patterns detected.