CVE-2025-9231
CVE-2025-9231 is a medium-severity vulnerability with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-385.
Key facts
- Severity: Medium (CVSS 3.x base score 6.5)
- EPSS exploit prediction: 2% (81st percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-31728
- Weakness: CWE-385
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2025-9231?
- 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.
- How severe is CVE-2025-9231?
- CVE-2025-9231 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.
- Is CVE-2025-9231 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2025-9231?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2025-9231 have an EU (EUVD) identifier?
- Yes. CVE-2025-9231 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-31728.
- When was CVE-2025-9231 published?
- CVE-2025-9231 was published on 2025-09-30 and last updated on 2026-06-17.
References
- https://github.com/openssl/openssl/commit/567f64386e43683888212226824b6a179885a0fe
- https://github.com/openssl/openssl/commit/cba616c26ac8e7b37de5e77762e505ba5ca51698
- https://github.com/openssl/openssl/commit/eed5adc9f969d77c94f213767acbb41ff923b6f4
- https://github.com/openssl/openssl/commit/fc47a2ec078912b3e914fab5734535e76c4820c2
- https://openssl-library.org/news/secadv/20250930.txt
- http://www.openwall.com/lists/oss-security/2025/09/30/5
- http://www.openwall.com/lists/oss-security/2026/05/11/11
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
- https://cert-portal.siemens.com/productcert/html/ssa-089022.html
- https://cert-portal.siemens.com/productcert/html/ssa-253495.html
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