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Fencer Vulns
medium 5.9

CVE-2023-6935 json

Marvin Attack vulnerability in SP Math All RSA

published 2024-02-09 2 y ago modified 2026-07-25 3 mo ago also EUVD-2023-59133 , GHSA-r36f-f47x-637q , JLSEC-2026-677

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

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.

Patch / fix

  • julia wolfSSL_jll 5.7.2+0
  • wolfssl wolfssl 5.6.6
  • wolfssl Debian 13 5.6.6-1.2

debian advisories DEBIAN-CVE-2023-6935

  • wolfssl Alpine 3.24, Alpine 3.23, Alpine 3.22 +3 more 5.6.6-r0

alpine advisories ALPINE-CVE-2023-6935

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
OSV 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
julia wolfSSL_jll
<5.7.2+0
5.7.2+0

Affected products

  • wolfSSL wolfSSL

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.