fix(security): sanitize gstack-slug output against shell injection#138
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elliotllliu wants to merge 1 commit intogarrytan:mainfrom
Open
fix(security): sanitize gstack-slug output against shell injection#138elliotllliu wants to merge 1 commit intogarrytan:mainfrom
elliotllliu wants to merge 1 commit intogarrytan:mainfrom
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The eval $(gstack-slug) pattern used across 14+ skill templates passes git-derived values (remote URL, branch name) through eval without stripping shell metacharacters like ;, $(), backticks, |. Add a sanitize function that strips everything except [a-zA-Z0-9._-] from both SLUG and BRANCH before output. This hardens all existing callers without requiring changes to any template file. Risk was low (GitHub/GitLab enforce safe naming) but defense-in-depth matters for self-hosted git servers or exotic remote URLs. Fixes garrytan#133
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Summary
Fixes #133 — hardens
bin/gstack-slugagainst shell injection when consumed viaeval $(gstack-slug).Problem
gstack-slugderives SLUG and BRANCH fromgit remote get-url originandgit rev-parse --abbrev-ref HEAD. The existing pipeline (sed+tr '/' '-') does not strip shell metacharacters like;,$(), backticks, or|. Since the output is consumed viaevalin 14+ skill templates, a malicious remote URL or branch name could execute arbitrary commands.Fix
Added a
sanitize()function that strips everything except[a-zA-Z0-9._-]viatr -cd. Applied to both SLUG and BRANCH before output. All existingeval $(gstack-slug)callers are automatically protected without template changes.Risk context
Low severity — GitHub and GitLab enforce alphanumeric naming for orgs/repos/branches, so hosted repos are safe. This is defense-in-depth for self-hosted git servers or exotic remote URLs.