CVE-2023-4421

2023-12-1217:15:08

CWE-203

[email protected]

web.nvd.nist.gov

cve-2023-4421

nss

pkcs#1 v1.5

bleichenbacher attack

timing side-channel

marvin attack

vulnerability

6.5 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

6.2 Medium

AI Score

Confidence

High

0.0005 Low

EPSS

Percentile

18.3%

JSON

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.

Affected configurations

Vulners

NVD

Node

mozillanssRange≤3.61

VendorProductVersionCPE
mozillanss*cpe:2.3:a:mozilla:nss:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
mozilla	nss	*	cpe:2.3:a:mozilla:nss::::::::

CNA Affected

[
  {
    "product": "NSS",
    "vendor": "Mozilla",
    "versions": [
      {
        "lessThan": "3.61",
        "status": "affected",
        "version": "unspecified",
        "versionType": "custom"
      }
    ]
  }
]