MCP Git Server capability laundering: git_init enables credential exfiltration

Capability Laundering in MCP 2: CVE-2025-68143 Anthropic Git MCP Server Path Traversal to Credential Exfiltration

What Happened In our previous analysis, we identified capability laundering in Anthropic’s Memory MCP Server: a “memory storage” tool that could write arbitrary configuration files through unconstrained implementation. This is the second case. The MCP Git Server (mcp-server-git) exposes Git operations to AI agents. The git_init tool accepts arbitrary repo_path values without validation, creating repositories in any filesystem location. Combined with git_diff_staged, this turns a “Git helper” into a credential exfiltration primitive. ...

December 28, 2025 · 7 min · 1369 words · Aonan Guan
Memory MCP Server capability laundering: bypassing approval gates through MCP side effects

Capability Laundering in MCP: Anthropic Memory Server to Terminal Hijacking

What Happened Anthropic’s Memory MCP Server is designed to help AI agents remember information across conversations by storing entities in a knowledge graph JSON Lines (JSONL) file. According to its documentation, each entity should only contain name, entityType, and observations. However, the vulnerable implementation accepted and stored additional properties beyond what was documented. That turned “memory persistence” into arbitrary JSON injection, enabling persistent VS Code configuration injection and terminal profile hijacking. ...

December 27, 2025 · 8 min · 1647 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

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