CVE-2023-6935

2024-02-0923:15:08

CWE-203

[email protected]

web.nvd.nist.gov

cve-2023-6935

wolfssl

math

rsa

marvin attack

bleichenbacher

security vulnerability

5.9 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

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

5.5 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

9.2%

JSON

wolfSSL SP Math All RSA implementation is vulnerable to the Marvin Attack, new variation of a timing Bleichenbacher style attack, when built with the following options to configure:

–enable-all CFLAGS=“-DWOLFSSL_STATIC_RSA”

The define “WOLFSSL_STATIC_RSA” enables static RSA cipher suites, which is not recommended, and has been disabled by default since wolfSSL 3.6.6. Therefore the default build since 3.6.6, even with “–enable-all”, is not vulnerable to the Marvin Attack. The vulnerability is specific to static RSA cipher suites, and expected to be padding-independent.

The vulnerability allows an attacker to decrypt ciphertexts and forge signatures after probing with a large number of test observations. However the server’s private key is not exposed.

CNA Affected

[
  {
    "defaultStatus": "unaffected",
    "modules": [
      "RSA"
    ],
    "product": "wolfSSL",
    "repo": "https://github.com/wolfSSL/wolfssl",
    "vendor": "wolfSSL",
    "versions": [
      {
        "lessThanOrEqual": "5.6.4",
        "status": "affected",
        "version": "3.12.2",
        "versionType": "release bundle"
      }
    ]
  }
]