Vulnerability in Wolfssl
CVE-2023-6935
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.
EPSS: 0.005 (42.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Wolfssl — versions 3.12.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- facts@wolfssl.com (Technical Description, technical-description, third-party-advisory)
- facts@wolfssl.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2023-6935?
- CVE-2023-6935 is a medium-severity vulnerability in Wolfssl, classified under Observable Discrepancy. CVSS score: 5.9/10. Published 2024-02-09.
- How severe is CVE-2023-6935?
- Medium severity. CVSS v3 base score is 5.9 out of 10.
- Is CVE-2023-6935 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.