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Potential fix for code scanning alert no. 40: Checkout of untrusted code in a non-privileged context #2319

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Potential fix for code scanning alert no. 40: Checkout of untrusted code in a non-privileged context #2319

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badeff7
Potential fix for code scanning alert no. 40: Checkout of untrusted c…
don-petry Oct 12, 2026
12a7ef3
fix(reviews): pass inputs.agent_ref via env instead of interpolating …
don-petry Oct 12, 2026
dd2da29
Merge branch 'main' into alert-autofix-40
don-petry Nov 7, 2026
a34bd81
fix(ci): auto-fix for CodeQL [skip ci-relay]
don-petry Nov 7, 2026
50675f3
Merge branch 'main' into alert-autofix-40
don-petry Nov 7, 2026
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33 changes: 32 additions & 1 deletion .github/workflows/dev-lead-reusable.yml
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Original file line number Diff line number Diff line change
Expand Up @@ -257,13 +257,44 @@ jobs:
with:
token: ${{ secrets.GH_PAT_DON_PETRY_WRITER || secrets.GH_PAT_DON_PETRY || secrets.GH_PAT_WORKFLOWS || github.token }}

- name: Validate dev-lead ref input
id: agent-ref
shell: bash
env:
AGENT_REF: ${{ inputs.agent_ref }}
run: |
ref="$AGENT_REF"
if [ -z "$ref" ]; then
ref="main"
fi

# Block untrusted PR refs and unsafe ref formats.
if [[ "$ref" =~ ^refs/pull/ ]]; then
echo "::error::inputs.agent_ref must not be a pull-request ref: $ref"
exit 1
fi
if [[ "$ref" =~ ^[0-9a-fA-F]{40}$ ]]; then
echo "::error::inputs.agent_ref must not be a raw commit SHA: $ref"
exit 1
fi
if [[ "$ref" == *".."* || "$ref" == *":"* || "$ref" =~ [[:space:]] ]]; then
echo "::error::inputs.agent_ref contains unsafe characters: $ref"
exit 1
fi
if [[ ! "$ref" =~ ^[A-Za-z0-9._/-]+$ ]]; then

@don-petry don-petry Oct 23, 2026

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[High] The character-class check ^[A-Za-z0-9._/-]+$ (combined with only blocking ^refs/pull/ and 40-char hex SHAs) still allows untrusted refs: actions/checkout resolves shorthand PR refs (pull/<n>/head, pull/<n>/merge), abbreviated commit SHAs (7–39 hex chars), and arbitrary unmerged branch names, all of which match ^[A-Za-z0-9._/-]+$. In addition, writing $ref to $GITHUB_ENV on line 278 triggers a new CodeQL Environment variable built from user-controlled sources alert, and the second Checkout dev-lead scripts step in the downstream job remains unvalidated. Validate $ref against an explicit allowlist of valid dev-lead channel/release refs (^main$|^dev-lead/(v[0-9]+(\.[0-9]+\.[0-9]+|-(stable|next|ring[0-9]+))|stable|next|ring[0-9]+)$) and pass it via $GITHUB_OUTPUT (steps.<id>.outputs.ref) in both jobs.

echo "::error::inputs.agent_ref contains invalid characters: $ref"
exit 1
fi

echo "ref=$ref" >> "$GITHUB_OUTPUT"

- name: Checkout dev-lead scripts
uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
with:
repository: combsmith/.github-private
# Pinned channel (e.g. dev-lead/stable) when a trigger stub passes it;
# defaults to "main" → unchanged behaviour (#535/#506).
ref: ${{ inputs.agent_ref }}
ref: ${{ steps.agent-ref.outputs.ref }}
path: .dev-lead
# Cross-repo callers: github.token cannot read a private org repo — ensure
# GH_PAT_WORKFLOWS is set as an org or repo secret in the calling repo.
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