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CVE-2023-4421 Detail


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.


NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NVD assessment not yet provided.

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Hyperlink Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1651411 Issue Tracking 
https://www.mozilla.org/security/advisories/mfsa2023-53/ Issue Tracking  Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-203 Observable Discrepancy cwe source acceptance level NIST  

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Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
NVD Published Date:
NVD Last Modified:
Mozilla Corporation