[sec-check] fix: verify SHA-256 before installing cosign release asset in install-cosign action - #434
Open
kubestellar-hive[bot] wants to merge 1 commit into
Open
[sec-check] fix: verify SHA-256 before installing cosign release asset in install-cosign action#434kubestellar-hive[bot] wants to merge 1 commit into
kubestellar-hive[bot] wants to merge 1 commit into
Conversation
![sec-check[bot]](https://github.githubassets.com/images/gravatars/gravatar-user-420.png){kind=avatar}
install-cosign downloaded the cosign binary and installed it executable (optionally via sudo) with no integrity check. Now the install step verifies the asset against a SHA-256 pinned in the action for the default v3.0.6 release (values cross-checked against upstream cosign_checksums.txt), requires an expected-sha256 input for any other release, and fails closed when no checksum is available. The cross-version cache restore-keys fallback is removed so a prefix match cannot restore a binary from a different release. Refs #433 Signed-off-by: sec-check[bot] <sec-check[bot]@users.noreply.github.com>
Dependency Review✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.Scanned FilesNone |
kubestellar-hive
Bot
added
security
agent/security
This was referenced Aug 29, 2026
hanthor
approved these changes
Sep 2, 2026
hanthor
left a comment
hanthor
left a comment
Member
There was a problem hiding this comment.
Sec-check fix: adds SHA-256 verification before installing the cosign release asset. Independently fetched the real cosign_checksums.txt from the v3.0.6 GitHub release and all 4 pinned hashes matched exactly. Fails closed on a missing/mismatched checksum, and the restore-keys cache-poisoning vector is correctly removed. CI green (5/5).
Generated by Claude Code
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Security Fix
Cluster:
.github/actions/install-cosign/action.yml(only file touched)The composite action downloaded the cosign release binary and installed it executable (optionally via
sudo) with no integrity verification — cosign handles image-signing key material, so an unverified install is a supply-chain weak point. The action has no current callers (in-repo signing uses SHA-pinnedsigstore/cosign-installer), but it is public on thev1tag and callable by any consumer.What changes:
install -m 0755.cosign_checksums.txtfrom the sigstore/cosign release.expected-sha256input — required for any non-defaultcosign-release; the step fails closed when no checksum is available.restore-keysprefix (cosign-${os}-${arch}-) could restore a binary from a different cosign release than requested; cache is now exact-key only.No behavior change for the default path beyond the verification gate (hashes match upstream, so legitimate installs proceed identically).
Refs #433
Filed by sec-check agent (ACMM L4/L5 — hold-gated mode). Hold-gated: human review required. Hold label must remain until human merge.
— hive: agent=sec-check backend=copilot model=kimi-k3