Agent SkillSlip: Path traversal in Gemini CLI skill installation writes to .vscode

Agent SkillSlip: Path Traversal in Google Gemini CLI, Anthropic Claude Code, and Vercel add-skill

TL;DR Agent SkillSlip is a class of path traversal vulnerabilities in AI agent skill/plugin installers. The name field inside skill metadata is used directly in path.join() without validation, writing files to attacker-controlled locations — but the user only sees the archive filename or repository URL, not the internal metadata Found across three tools: Gemini CLI, Claude Code, and Vercel’s add-skill Impact ranges from VS Code terminal hijacking to SSH key injection add-skill fixed in PR #8 and PR #108. Gemini CLI and Claude Code remain unpatched as of writing The Pattern After installing a Gemini CLI skill: .vscode/settings.json injected, terminal hijacked ...

March 8, 2026 · 10 min · 2008 words · Aonan Guan
CVE-2025-66479: The CVE That Claude Code Never Got

CVE-2025-66479: Anthropic's Silent Fix and the CVE That Claude Code Never Got

allowedDomains: [], “Empty array = no network access.” — Anthropic Sandbox Runtime Documentation The implementation did not match the documentation. When I configured Claude Code’s sandbox with allowedDomains: [], expecting complete network isolation, the sandbox was wide open and allowed connections to any server on the internet. Anthropic patched this quietly in Claude Code v2.0.55 with a changelog entry saying “Fix proxy DNS resolution” — no mention of a critical security flaw. They assigned CVE-2025-66479 to their runtime library but did not assign a CVE to their flagship product Claude Code. The changelog did not include a security advisory. In practice, the issue was fixed quietly and most users were unlikely to realize there was a security patch. ...

December 3, 2025 · 6 min · 1138 words · Aonan Guan
CVE-2025-55322: Microsoft OmniParser GUI Agent

Click, Parse, Execute - When a GUI Agent's Control Plane Becomes a Remote Control Surface

A Remote Code Execution about modern “Computer Use” agents, Microsoft’s OmniParser/OmniTool, and what happens when capability meets reachability. “In agent stacks, every HTTP port that can do things is a pair of hands. Make sure they’re yours.” Video from Microsoft TL;DR While mapping Microsoft’s OmniParser/OmniTool , I followed the path from prompt → parsing → action and found a reachable, unauthenticated execution surface on the VM controller. If the service is network-accessible, that path becomes remote code execution (RCE) remote control by design. Attackers can send command directly to control the GUI Agent running on the computer. Microsoft acknowledged the issue (MSRC Case 97706), shipped a fix, and has assigned CVE-2025-55322 (https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-55322). Upgrade and harden now. ...

September 25, 2025 · 5 min · 1019 words · Aonan Guan

Three Dots to Root: How I Found a Path Traversal in Microsoft's Agentic Web (NLWeb)

Discovered a classic path traversal vulnerability in Microsoft’s new Agentic Web protocol (NLWeb) that could expose sensitive files including API keys, credentials, and configuration files. The vulnerability was particularly critical as it could compromise AI agents’ “cognitive engines” by leaking LLM API keys. The research was featured in an exclusive interview with The Verge and subsequently covered by 30+ international media outlets across 15+ countries in 10+ languages, including PCWorld, IT Pro, Neowin, Tom’s Guide, CIO Korea, 3DNews Russia, iSpazio Italy, and Dagens AI Denmark. ...

August 6, 2025 · 1 min · 93 words · Aonan Guan