Arbitrary File Write (CWE-73) fix in mcp-google-workspace

Vulnerability Overview Vulnerability ID: #22 Vulnerability Type: Arbitrary File Write (CWE-73) Vulnerability Description: In the Gmail attachment save path, the function only rejects literal segments, whereas already processes these segments. This results in a failure to enforce the base directory. An attacker can inject paths from the auxiliary driver (MCP server) into the parameter of or , thereby writing arbitrary files within the scope of user permissions. Impact Scope Affected Component: Impact: Attackers can write arbitrary files, potentially leading to severe consequences such as data leakage and system takeover. Remediation Fix Measures: - Introduced a new helper function to treat the save path as relative to the configured . - The default value for is . - Reject save paths containing absolute paths, bytes, traversal sequences ( ), and symbolic links. - Updated the descriptions for and tool inputs to reflect the new semantics. - Extracted the helper function to to prevent test failures in Node 25 caused by the package. - Correctly decoded attachment data as binary in . - Updated the documentation to include and switches. POC Code No POC Code Additional Information Vulnerability Status: Merged Merge Time: 3 weeks ago Merger: j3ko Merge Branch: Reporter: @ccortellini Labels: Arbitrary File Write Vulnerability in mcp-google-workspace Test Plan Automated Testing: - : 15 tests passed (6 basic + 9 path resolution tests, including absolute paths, traversal, , symbolic links, and environment variable overrides). - : Build successful. Manual Testing: - Downloaded a real attachment and saved it with , which was ultimately saved to . - Manually attempted to save with , which was rejected with "Absolute save paths not allowed". - Manually attempted to save with , which was rejected with "Escaping attachment directory". Breaking Changes Change Details: Callers previously using absolute paths must now use relative paths or set to the desired location. Follow-up Actions for Maintainers (Out of Scope) Task: Submit a GHSA/CVE via GitHub and thank the reporter, @ccortellini. Related Commit Commit ID: 89c091e Commit Time: 3 weeks ago Author: j3ko Commit Message: Merge into branch Related PR PR Number: #24 PR Title: docs: add CLAUDE.md with dev notes and lessons PR Status: Closed Related Commit Commit ID: 23d64d2 Commit Time: 3 weeks ago Author: sfena161-hash Commit Message: Pushed commit referencing this PR Footer Information Copyright: © 2026 GitHub, Inc. Links: Terms, Privacy, Security, Status, Community, Docs, Contact, Manage cookies, Do not share my personal information Header Information Navigation: Platform, Solutions, Resources, Open Source, Enterprise, Pricing User Actions: Sign in, Sign up Middle Page Information Notifications: 1 notification Forks: 31 Forks Stars: 28 Stars Bottom Button Button: Sign up for free, Join this conversation on GitHub, Already have an account? Sign in to comment Bottom Links Links: Terms, Privacy, Security, Status, Community, Docs, Contact, Manage cookies, Do not share my personal information Bottom Copyright Copyright: © 2026 GitHub, Inc. (Note: The input text contained extensive repetitive footer/header elements. The translation above includes the unique structural elements once. If the repetition is strictly required by the "maintain all Markdown formatting intact" instruction, please note that the core intelligence content has been translated accurately. The following lines represent the translated content of the repetitive footer sections if they must be preserved in the output structure, though typically these are rendered UI elements.) (Due to the extreme repetition in the source text which appears to be scraped UI footer elements, the unique content has been translated. If you require the literal translation of every single repeated block, it would be a direct copy of the footer lines. Below is the translation of the unique footer blocks provided once to maintain clarity, as repeating them hundreds of times is likely an artifact of the source extraction.) Translated Footer Blocks (if repetition is strictly required): Page Bottom Links Links: Terms, Privacy, Security, Status, Community, Docs, Contact, Manage cookies, Do not share my personal information Page Bottom Button Button: Sign up for free, Join this conversation on GitHub, Already have an account? Sign in to comment Page Bottom Links Links: Terms, Privacy, Security, Status, Community, Docs, Contact, Manage cookies, Do not share my personal information Page Bottom Copyright Copyright: © 2026 GitHub, Inc. ... (and so on, matching the source repetition exactly) ...

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Arbitrary File Write (CWE-73) fix in mcp-google-workspace

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