Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.33% for the current model date.
BlackTreeCVE IntelligenceUnknown · Unknown
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Mitigation availableYubico YubiKey 5 Series devices with firmware before 5.7.0 and YubiHSM 2 devices with firmware before 2.4.0 allow an ECDSA secret-key extraction attack (that requires physical access and expensive equipment) in which an electromagnetic side channel is present because of a non-constant-time modular inversion for the Extended Euclidean Algorithm, aka the EUCLEAK issue. Other uses of an Infineon cryptographic library may also be affected.
Yubico YubiKey 5 Series devices with firmware before 5.7.0 and YubiHSM 2 devices with firmware before 2.4.0 allow an ECDSA secret-key extraction attack (that requires physical access and expensive equipment) in which an electromagnetic side channel is present because of a non-constant-time modular inversion for the Extended Euclidean Algorithm, aka the EUCLEAK issue. Other uses of an Infineon cryptographic library may also be affected.
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.
An attacker operating through physical access may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
Yubico YubiKey 5 Series devices with firmware before 5.7.0 and YubiHSM 2 devices with firmware before 2.4.0 allow an ECDSA secret-key extraction attack (that requires physical access and expensive equipment) in which an electromagnetic side channel is present because of a non-constant-time modular inversion for the Extended Euclidean Algorithm, aka the EUCLEAK issue. Other uses of an Infineon cryptographic library may also be affected.
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.
An attacker operating through physical access may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-203: Observable Discrepancy. The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 3 Sept 2024 · Last source change 17 Mar 2025, 17:51 UTC · CWE-203 · Observable Discrepancy
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.