Vulnerability · Published Sep 30, 2025 · Assigned by openssl

CVE-2025-9231Timing side-channel in SM2 algorithm on 64 bit ARM

Medium 6.5

In plain English

A medium-severity security flaw in OpenSSL from OpenSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.2% (higher than 83% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)2.2%top 17.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20openssl3.3.5-r0ALPINE-CVE-2025-9231
Alpine:v3.21openssl3.3.5-r0ALPINE-CVE-2025-9231
Alpine:v3.22openssl3.5.4-r0ALPINE-CVE-2025-9231
Alpine:v3.23openssl3.5.4-r0ALPINE-CVE-2025-9231
Alpine:v3.24openssl3.5.4-r0ALPINE-CVE-2025-9231
Debian:13openssl3.5.1-1+deb13u1DEBIAN-CVE-2025-9231
Debian:14openssl3.5.4-1DEBIAN-CVE-2025-9231
Ubuntu:22.04:LTSopenssl3.0.2-0ubuntu1.20USN-7786-1
Ubuntu:24.04:LTSopenssl3.0.13-0ubuntu3.6USN-7786-1
Ubuntu:25.10openssl3.5.3-1ubuntu2UBUNTU-CVE-2025-9231
Ubuntu:26.04:LTSopenssl3.5.3-1ubuntu2UBUNTU-CVE-2025-9231

Affected products (as reported)

VendorProductVersions
OpenSSL OpenSSL 3.5.0 – before 3.5.43.4.0 – before 3.4.33.3.0 – before 3.3.53.2.0 – before 3.2.6

Weakness: CWE-385 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

References