Id:
CVE-2023-4421
Comment
:
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.
CVSSv3 Score:
6.5
Attack vector:
|
NETWORK
|
Attack complexity:
|
LOW
|
Privileges required:
|
LOW
|
User interaction:
|
NONE
|
Scope:
|
UNCHANGED
|
Confidentiality impact:
|
HIGH
|
Integrity impact:
|
NONE
|
Availability impact:
|
NONE
|
CVSSv3 Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
References: