A critical cryptographic vulnerability in jahlives openssl_encrypt allows unauthenticated attackers to bypass integrity checks via an insecure fallback mechanism.

The vulnerability exists in the pqc.py module, where a failure in AES-GCM decryption causes the system to fall back to an unauthenticated AES-CTR mode. This allows unauthenticated remote attackers to modify ciphertext in transit and perform bit-flipping attacks that bypass all integrity verification.

Successful exploitation allows for the modification of encrypted data in transit, which can lead to command injection or the manipulation of sensitive information. This compromises the fundamental security of encrypted communications, rendering the encryption effectively useless against an active adversary. Given the CVSS score of 9.8, this is a critical threat to data integrity.

Immediate Action: Update jahlives openssl_encrypt to version 1.4.0 or later to remove the insecure fallback mechanism.

Proactive Monitoring: Monitor for anomalous decryption failure rates or unexpected traffic patterns that may indicate attempts to trigger the fallback mechanism.

Compensating Controls: Utilize end-to-end encryption protocols that do not rely on this library or implement additional message authentication codes (MACs) to ensure data integrity.

Public Exploit Available: No

The integrity of encrypted data is paramount, and this flaw effectively invalidates the security promises of the affected component. Remediation should be prioritized immediately to ensure that all communications are protected by authenticated encryption only.