NSS <=3.60 PKCS#1 v1.5 Timing SideChannel Leak
CVE-2023-4421 Published on December 12, 2023
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.
Products Associated with CVE-2023-4421
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Affected Versions
Mozilla NSS:- Version unspecified and below 3.61 is affected.
Exploit Probability
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