Vulnerabilities > CVE-2023-4421 - Information Exposure Through Discrepancy vulnerability in Mozilla NSS
Attack vector
NETWORK Attack complexity
LOW Privileges required
LOW Confidentiality impact
HIGH Integrity impact
NONE Availability impact
NONE Summary
The NSS code used for checking PKCS#1 v1.5 was leaking information useful in mounting Bleichenbacher-like attacks. Both the overall correctness of the padding as well as the length of the encrypted message was leaking through timing side-channel. By sending large number of attacker-selected ciphertexts, the attacker would be able to decrypt a previously intercepted PKCS#1 v1.5 ciphertext (for example, to decrypt a TLS session that used RSA key exchange), or forge a signature using the victim's key. The issue was fixed by implementing the implicit rejection algorithm, in which the NSS returns a deterministic random message in case invalid padding is detected, as proposed in the Marvin Attack paper. This vulnerability affects NSS < 3.61.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 13 |