MediumCVE-2025-9231

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

    Published Sources: Red Hat, Siemens ProductCERT, BSI, Ubuntu, Msrc Update Guide, SUSE, CVE.org, EUVD

    What is affected, what to do

    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..

    Update OpenSSL to version 3.5.4, OpenSSL to version 3.4.3, OpenSSL to version 3.3.5.

    Affected
    • OpenSSL lt 3.5.0..3.5.4
    • OpenSSL lt 3.4.0..3.4.3
    • OpenSSL lt 3.3.0..3.3.5
    • OpenSSL lt 3.2.0..3.2.6
    Fixed in
    • OpenSSL 3.5.4
    • OpenSSL 3.4.3
    • OpenSSL 3.3.5
    • OpenSSL 3.2.6

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    6.5

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    6.5

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: Red Hat, Siemens ProductCERT, BSI, Ubuntu, Msrc Update Guide, SUSE, CVE.org, EUVD

    2.2 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 82.7

    Show all metrics
    Severity
    Medium
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    98.50 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    6.5 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    6.5
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    2.2 %
    Moderate — model estimates 1-10% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    82.7
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-385

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    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.

    Source: redhat_csaf, siemens_advisory, BSI WID Portal, BSI CSAF, Ubuntu Security Notices, Microsoft Security Update Guide, suse_csaf, cvelistv5, NVD (NIST), CVE.org (MITRE), ENISA EUVD

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    OpenSSLOpenSSL
    • 3.3.0 – < 3.3.5
    • 3.4.0 – < 3.4.3
    • 3.5.0 – < 3.5.4
    • 3.2.0 – < 3.2.6
    • 3.3.5
    • 3.4.3
    • 3.5.4
    • 3.2.6
    DellSecure Connect Gateway Appliance
    • < 5.32.00.18
    • 5.32.00.18
    IBMAIX
    • 7.2
    • 7.3
    • —
    • —
    IBMDevOps Code ClearCase
    • < 11.0.0.05
    • < 10.0.1.05
    • < 9.1.0.10
    • 11.0.0.05
    • 10.0.1.05
    • 9.1.0.10
    IBMMQ
    • Operator
    • Container
    • —
    • —
    IBMTXSeries
    • for multiplatforms
    • —
    IBMVIOS
    • 3.1
    • 4.1
    • —
    • —
    IGELOS
    • < 12.7.4
    • < 11.11.100
    • 12.7.4
    • 11.11.100
    MeinbergLANTIME
    • < 7.10.004
    • 7.10.004
    Open SourceOpenSSL
    • < 3.4.3
    • < 3.3.5
    • < 3.2.6
    • < 3.5.4
    • 3.4.3
    • 3.3.5
    • 3.2.6
    • 3.5.4
    Red HatOpenShift Container Platform
    • < 4.14.62
    • 4.14.62
    SolarWindsPlatform
    • < 2026.1
    • 2026.1
    SplunkSplunk Enterprise
    • < 10.0.3
    • Universal Forwarder
    • < 9.4.8
    • < 9.3.9
    • < 10.2.0
    • < 9.2.12
    • 10.0.3
    • —
    • 9.4.8
    • 9.3.9
    • 10.2.0
    • 9.2.12
    XeroxFreeFlow Print Server
    • <9.0 SP-3 (93.M3.14.86)
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxubuntuopensslbionic
    Linuxubuntuopensslfocal
    Linuxubuntuopenssljammy
    Linuxubuntuopensslnoble
    Linuxubuntuopensslplucky
    Linuxubuntuopenssltrusty
    Linuxubuntuopensslxenial
    Linuxubuntuopenssl1.0bionic

    Weakness classes (CWE)

    • CWE-385Covert Timing Channel

      Base

      Covert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information.

      Entry at MITRE CWE-385

    References & sources

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