SB2023121264 - Timing side-channel attack in Mozilla NSS

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Main Vulnerability Database SB2023121264

SB2023121264 - Timing side-channel attack in Mozilla NSS

Published: December 12, 2023

Security Bulletin ID SB2023121264
Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Covert Timing Channel (CVE-ID: CVE-2023-4421)

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to 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.


Remediation

Install update from vendor's website.

References