mews/pos through 2.0.0 Missing Hash Verification in 3D Pay and 3D Host Callbacks

Summary

mews/pos through 2.0.0 contains an insufficient verification of data authenticity vulnerability that allows unauthenticated attackers to forge payment results by submitting unverified callbacks. GarantiPos, PayForPos and InterPos 3D Pay and 3D Host handlers skip check3DHash(), letting attackers post tampered status, amount or order ID fields to complete orders without paying.

Remediation

1. Inventory every mewebstudio pos deployment, including staging.
2. No fixed version appears in the public sources yet. Check the references below and the vendor directly.

References

• Patchhttps://github.com/mewebstudio/pos/commit/7c59d42bc49483c7c54999d757cb67055d9f732a
• Patchhttps://github.com/mewebstudio/pos/pull/305
• Advisoryhttps://www.vulncheck.com/advisories/mews-pos-through-2.0.0-missing-hash-verification-in-3d-pay-and-3d-host-callbacks
• Referencehttps://github.com/mewebstudio/pos
• Referencehttps://github.com/mewebstudio/pos/blob/50ed2bfe4f8980b8b0c47996de571943fa58d7ad/src/Gateway/InterPos.php#L134-L149
• Referencehttps://github.com/mewebstudio/pos/blob/50ed2bfe4f8980b8b0c47996de571943fa58d7ad/src/Gateway/PayForPos.php#L135-L150
• Referencehttps://github.com/mewebstudio/pos/issues/306