fix(sdk): prevent shell injection in MCP config via proper escaping#1276
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kagura-agent wants to merge 3 commits intoe2b-dev:mainfrom
Open
fix(sdk): prevent shell injection in MCP config via proper escaping#1276kagura-agent wants to merge 3 commits intoe2b-dev:mainfrom
kagura-agent wants to merge 3 commits intoe2b-dev:mainfrom
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…llQuote Use shlex.quote() (Python) and a shellQuote() helper (JS/TS) to properly escape the JSON-serialized MCP config before interpolating it into the shell command. Previously, single quotes in config values (API keys, tokens, URLs) could break out of shell quoting and allow arbitrary command execution inside the sandbox. Fixes e2b-dev#1154
kagura-agent
requested review from
ValentaTomas,
jakubno and
mishushakov
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🦋 Changeset detectedLatest commit: 89fe756 The changes in this PR will be included in the next version bump. This PR includes changesets to release 1 package
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Summary
Fixes #1154
When creating a sandbox with an
mcpconfig, the JSON-serialized config is interpolated directly into a shell command wrapped in single quotes. Sincejson.dumps()/JSON.stringify()do not escape single quotes, any MCP config value containing a single quote (e.g., API keys, tokens, URLs) breaks out of shell quoting and allows arbitrary command execution inside the sandbox.Changes
Python SDK (
sandbox_async/main.py,sandbox_sync/main.py)shlex.quote()to properly escape the JSON config string (4 locations)shlex.quote()is a stdlib function designed exactly for this purposeJS/TS SDK (
sandbox/index.ts)shellQuote()helper that escapes single quotes using the standard'\'''pattern (equivalent to Python'sshlex.quote())Before / After
Before (vulnerable):
After (safe):
Testing
Verified escaping behavior for both Python (
shlex.quote) and JS (shellQuote) with the PoC from the issue — single quotes in config values are properly escaped and no longer allow shell breakout.