CVE-2023-4421 (GCVE-0-2023-4421)

Vulnerability from cvelistv5 – Published: 2023-12-12 17:02 – Updated: 2025-11-04 19:25
VLAI?
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.
Severity ?
No CVSS data available.
CWE
  • Timing side-channel in PKCS#1 v1.5 decryption depadding code
Assigner
References
Impacted products
Vendor Product Version
Mozilla NSS Affected: unspecified , < 3.61 (custom)
Create a notification for this product.
Credits
Hubert Kario
Show details on NVD website
To clipboard 

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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.