CVE-2023-6935

Summary

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.

Affected Software

Weaknesses

• CWE-203: CWE-203 Observable Discrepancy

Workarounds

• Do not enable static RSA cipher suites
• Use TLS 1.3
• Build with –enable-sp, or –enable-sp-asm

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: none
  • Automatable: no
  • Technical Impact: partial

CVE Program Container

Additional References

• https://people.redhat.com/~hkario/marvin/
• https://www.wolfssl.com/docs/security-vulnerabilities/

References

• https://people.redhat.com/~hkario/marvin/
• https://www.wolfssl.com/docs/security-vulnerabilities/

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