vscode-spell-checker is a basic spell checker that works well with code and documents. Prior to v4.5.4, DocumentSettings._determineIsTrusted treats the configuration value cSpell.trustedWorkspace as the authoritative trust flag. The value defaults to true (package.json) and is read from workspace configuration each time settings are fetched. The code coerces any truthy value to true and forwards it to ConfigLoader.setIsTrusted , which in turn allows JavaScript/TypeScript configuration files ( .cspell.config.js/.mjs/.ts , etc.) to be located and executed. Because no VS Code workspace-trust state is consulted, an untrusted workspace can keep the flag true and place a malicious .cspell.config.js ; opening the workspace causes the extension host to execute attacker-controlled Node.js code with the user’s privileges. This vulnerability is fixed in v4.5.4.
Weakness
During installation, installed file permissions are set to allow anyone to modify those files.
Potential Mitigations
- Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
- Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/1.html
- https://cwe.mitre.org/data/definitions/127.html
- https://cwe.mitre.org/data/definitions/81.html
References
- https://drive.google.com/file/d/1mT4SOkkHSHU6NFfKwekysydAd3FUAC6K/view?usp=sharing
- https://github.com/streetsidesoftware/vscode-spell-checker/commit/f39af9a3a6f2a939a57171a24161ed735d41c575
- https://github.com/streetsidesoftware/vscode-spell-checker/releases/tag/code-spell-checker-v4.5.4
- https://github.com/streetsidesoftware/vscode-spell-checker/security/advisories/GHSA-mggq-68mr-58vj