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GHSA-rc6v-5rmx-w5mv

LOW

arnika is affected by medium-severity issues in UDP rotation, PQC handling, and KMS TLS

Also known asGO-2026-5614
Published
May 15, 2026
Updated
Jun 25, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

Blast Radius

1 pkg affected
🐹github.com/arnika-project/arnika

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Three medium-severity issues in arnika affecting the UDP key-rotation protocol, PQC key file handling, and KMS TLS client. All require specific preconditions to exploit and do not allow direct code execution or immediate key extraction. A self-contained PoC is attached.

Details

  1. ACK timestamp not validated: udpserver.go:185 udpClient() verifies HMAC and packet type but never checks ackPkt.Timestamp. A MITM can capture one ACK, drop all subsequent DATA packets, and replay the stale ACK indefinitely. Primary advances PSK each rotation, backup stays on key 1, tunnel breaks. No PSK knowledge needed. The server side already has this check, the client does not. Fix: mirror the timestamp check already present on the server side.

  2. Empty PQC key file silently accepted: repositories/pqc.go:29 os.ReadFile follows symlinks. Empty file to base64.Decode("") = []byte{}, nil. HKDF runs on the QKD key alone while arnika logs [OK] HKDF derivation completed for QKD+PQC key. Requires write access to the directory containing PQC_PSK_FILE. Fix: validate decoded key is non-empty before derivation; enforce parent directory permissions in SECURITY.md.

  3. InsecureSkipVerify: true hardcoded: repositories/kms.go:61 KMS HTTP client unconditionally sets InsecureSkipVerify: true, overriding RootCAs. CA_CERTIFICATE is loaded but never consulted (dead code). Requires MITM between arnika and the KMS endpoint, which in typical deployments are co-located. Fix: remove the flag; RootCAs already holds the correct pool when CA_CERTIFICATE is configured.

PoC

See arnika_exploit.tar.gz. PoC shows observable behavior for each attack; the third one (KMS MITM) needs no custom code, any HTTPS proxy with a self-signed cert is enough.

Impact

Issues require network MITM or local directory write access to exploit. No direct key extraction or code execution. Primary impact is tunnel desync and silent security downgrade in hybrid QKD+PQC mode.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/arnika-project/arnikaall versions1.0.1

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/arnika-project/arnika. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update github.com/arnika-project/arnika to 1.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rc6v-5rmx-w5mv is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-rc6v-5rmx-w5mv is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-rc6v-5rmx-w5mv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary Three medium-severity issues in arnika affecting the UDP key-rotation protocol, PQC key file handling, and KMS TLS client. All require specific preconditions to exploit and do not allow direct code execution or immediate key extraction. A self-contained PoC is attached. ### Details 1) ACK timestamp not validated: `udpserver.go:185` `udpClient()` verifies HMAC and packet type but never checks `ackPkt.Timestamp`. A MITM can capture one ACK, drop all subsequent DATA packets, and replay the stale ACK indefinitely. Primary advances PSK each rotation, backup stays on key 1, tunnel break
O3 Security · Impact-Aware SCA

Is GHSA-rc6v-5rmx-w5mv in your dependencies?

O3 detects GHSA-rc6v-5rmx-w5mv across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.