Bug 2396055 (CVE-2025-9231)

Summary:	CVE-2025-9231 openssl: Timing side-channel in SM2 algorithm on 64 bit ARM
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	adudiak, anthomas, bkabrda, brasmith, bsmejkal, cochase, crizzo, csutherl, dbosanac, dranck, ehelms, ggainey, gotiwari, gtanzill, jachapma, jbuscemi, jcantril, jclere, jgrulich, jhorak, jmitchel, jreimann, juwatts, jvasik, jwendell, kaycoth, kshier, lball, mdessi, mhulan, mrizzi, mvyas, ngough, nmoumoul, osousa, pcattana, pcreech, pjindal, plodge, progier, rblanco, rcernich, rchan, rojacob, sdawley, security-response-team, smallamp, spichugi, ssidhaye, stcannon, szappis, tbordaz, teagle, tmalecek, tpopela, vashirov, vchlup, veshanka, vmugicag, yguenane
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the OpenSSL SM2 algorithm implementation on 64-bit ARM platforms. This vulnerability allows recovery of the private key via timing side-channel analysis during signature computations.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2400650, 2400651, 2400653, 2400656, 2400657, 2400652, 2400654, 2400655
Bug Blocks:
Deadline:	2025-09-30

Description OSIDB Bzimport 2025-09-17 12:21:22 UTC

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.

OpenSSL 3.1, 3.0, 1.1.1 and 1.0.2 are not vulnerable to this issue.

OpenSSL 3.5, 3.4, 3.3, and 3.2 are vulnerable to this issue.