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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-6935
• https://people.redhat.com/~hkario/marvin/
• https://www.wolfssl.com/docs/security-vulnerabilities/