CVE-2023-6935
CVE-2023-6935 is a medium-severity vulnerability in Wolfssl with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-203.
Key facts
- Severity: Medium (CVSS 3.x base score 5.9)
- EPSS exploit prediction: 1% (41st percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2023-59133
- Weakness: CWE-203
- Affected product: Wolfssl
- Published:
- Last modified:
Description
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.
Frequently asked questions
- What is 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.
- How severe is CVE-2023-6935?
- CVE-2023-6935 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2023-6935 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2023-6935?
- CVE-2023-6935 affects Wolfssl. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2023-6935?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2023-6935 have an EU (EUVD) identifier?
- Yes. CVE-2023-6935 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-59133.
- When was CVE-2023-6935 published?
- CVE-2023-6935 was published on 2024-02-09 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*
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