CVE-2025-9231

MEDIUM
MEDIUM Priority: 0.09 BB Relevance: 62/100
Published: 2025-09-30 Modified: 2026-11-09 First seen: 2026-11-06 Status: active

Attack Surface

Network No Auth No Interaction Conf. Impact

CVSS Vector Breakdown

AV: Network
AC: High
PR: None
UI: None
S: Unchanged
C: High
I: None
A: None

Description

Issue summary: A timing side-channel which could potentially allow remote recovery of the private key exists in the SM2 algorithm implementation on 64 bit ARM platforms. Impact summary: A timing side-channel in SM2 signature computations on 64 bit ARM platforms could allow recovering the private key by an attacker.. While remote key recovery over a network was not attempted by the reporter, timing measurements revealed a timing signal which may allow such an attack. OpenSSL does not directly support certificates with SM2 keys in TLS, and so this CVE is not relevant in most TLS contexts. However, given that it is possible to add support for such certificates via a custom provider, coupled with the fact that in such a custom provider context the private key may be recoverable via remote timing measurements, we consider this to be a Moderate severity issue. The FIPS modules in 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this issue, as SM2 is not an approved algorithm.

Weakness Classification (1)

Affected Software (9)

VendorProductVersion
OpenSSL OpenSSL 3.5.0 < 3.5.4
OpenSSL OpenSSL 3.4.0 < 3.4.3
OpenSSL OpenSSL 3.3.0 < 3.3.5
OpenSSL OpenSSL 3.2.0 < 3.2.6
openssl openssl 1.0.2 – 1.0.2zm
siemens ruggedcom_rst2428p_firmware < 4.0
siemens sidis_secured_smartplug_firmware < 7.26.0310
siemens simatic_cn_4100_firmware < 5.0
siemens sinec_os < 3.3

Bug Bounty Relevance

62 / 100
✓ Network accessible
✓ No authentication
✓ No user interaction

CVSS Score

5.9 / 10.0 v3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS — Exploitation Probability

1.60%
Raw Score 0.015980
Percentile 76.1%
Date 2026-11-13

EPSS Trend

2026-11-13
0.01598
2026-11-12
0.01598
2026-11-10
0.01541
2026-11-09
0.01470
2026-11-08
0.01470
2026-11-07
0.01345
2026-11-06
0.02242

Intelligence Sources

mitre ref →
nvd ref →