mcpsentry
An MCP tool-definition security scanner built on six regular-expression rules plus a runtime proxy. It can run in offline environments.
Timeline (last 90 days)
On the MCPTox benchmark, the number of blocks by the five scanners on 218 retained test tools were: WARDEN 171, mcp-shield 41, truecopy 27, mcp-audit 25, and mcpsentry 8.
After adding an <IMPORTANT> prefix to the MCPTox tools, mcp-audit jumped from 25 to 222, truecopy from 27 to 141, mcpsentry from 8 to 136, WARDEN reached 225/225, while mcp-shield was 41 both before and after.
On the 14,933 real packages, the block rates of the five scanners from low to high were: truecopy 1.7% (252), WARDEN 2.5% (369), mcp-audit 6.2% (928), mcpsentry 9.7% (1,449), and mcp-shield 35.9% (5,354).
After manually reviewing the 996-package sample, of mcp-shield's 339 blocks only 1 held up (3 others were debatable); all 58 of mcp-audit's were invalid; of mcpsentry's 112, 1 held and 1 was debatable; all 17 of truecopy's were invalid; and of WARDEN's own 23 blocks, 0 should have blocked directly and 4 were debatable.
mcpsentry's base64 pattern matches any combination of 40 letters and slashes, and JSON Schema paths and lists like PNG/JPG/HEIC/TIFF all trigger it.
All Facts (5)
On the MCPTox benchmark, the number of blocks by the five scanners on 218 retained test tools were: WARDEN 171, mcp-shield 41, truecopy 27, mcp-audit 25, and mcpsentry 8.
50%UnverifiedAfter adding an <IMPORTANT> prefix to the MCPTox tools, mcp-audit jumped from 25 to 222, truecopy from 27 to 141, mcpsentry from 8 to 136, WARDEN reached 225/225, while mcp-shield was 41 both before and after.
50%UnverifiedOn the 14,933 real packages, the block rates of the five scanners from low to high were: truecopy 1.7% (252), WARDEN 2.5% (369), mcp-audit 6.2% (928), mcpsentry 9.7% (1,449), and mcp-shield 35.9% (5,354).
50%UnverifiedAfter manually reviewing the 996-package sample, of mcp-shield's 339 blocks only 1 held up (3 others were debatable); all 58 of mcp-audit's were invalid; of mcpsentry's 112, 1 held and 1 was debatable; all 17 of truecopy's were invalid; and of WARDEN's own 23 blocks, 0 should have blocked directly and 4 were debatable.
50%Unverifiedmcpsentry's base64 pattern matches any combination of 40 letters and slashes, and JSON Schema paths and lists like PNG/JPG/HEIC/TIFF all trigger it.
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