Kong Event Gateway versions 1.0.0 through 1.1.1 and 1.2.0 do not enforce key rotation before reaching the NIST SP 800-38D recommended usage limit for AES-GCM encryption keys with random nonces when the AWS IAM encryption feature is enabled. Sustained high-rate message production without key rotation (which only occurs on instance reboot) increases the probability of nonce collisions. Such collisions can allow an authorized consumer to recover parts of plaintext from the affected encrypted messages. The vulnerability is fixed in versions 1.1.2 and 1.2.1 by enforcing automatic key rotation before the recommended usage limit is reached.

If exploited, an authorized consumer could recover partial plaintext from encrypted messages due to nonce reuse in AES-GCM encryption. This compromises message confidentiality to some extent. The vulnerability requires sustained high-rate message production without key rotation, which only happens on instance reboot, limiting the likelihood and impact. No known exploits in the wild have been reported.

A fix is available in Kong Event Gateway versions 1.1.2 and 1.2.1, which enforce automatic key rotation before the recommended usage limit for AES-GCM keys is reached. Users should upgrade to these versions to mitigate the vulnerability. Since this is a cloud service, the vendor manages remediation for the cloud-hosted service; users should verify with Kong's advisory for current status.