CVE-2023-6935 | Marvin Attack vulnerability in SP Math All RSA

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.

Published: 2024-02-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-6935 is rated Low Risk (38.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.54%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-6935

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.32% 0.54% +0.22%
2 2026-01-27 0.20% 0.32% +0.11%
3 2026-01-21 — 0.20% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-6935

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]

Weakness enumeration for CVE-2023-6935

OS Trackers for CVE-2023-6935

vendor priority summary link
alpine medium CVE-2023-6935: 1 source package rows (wolfssl); 15 state rows across 5 repos (3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 5, open 10. https://security.alpinelinux.org/vuln/CVE-2023-6935
debian unimportant CVE-2023-6935 unimportant priority: Debian including 1 source packages (wolfssl), 4 status rows across 4 suites (bookworm, bullseye, sid, trixie): open 2, resolved 2. https://security-tracker.debian.org/tracker/CVE-2023-6935
ubuntu medium CVE-2023-6935 medium priority: Ubuntu including 1 source packages (wolfssl), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 4, not-affected 4, ignored 3, released 1. https://ubuntu.com/security/CVE-2023-6935

Affected software / configurations for CVE-2023-6935

Vendor Product Version Raw CPE
wolfssl wolfssl >= 3.12.2, <= 5.6.4 cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*

References for CVE-2023-6935

cvelogic Threat Intelligence