CVE-2021-43392

STMicroelectronics STSAFE-J 1.1.4, J-SAFE3 1.2.5, and J-SIGN sometimes allow attackers to obtain information on cryptographic secrets. This is associated with the ECDSA signature algorithm on the Java Card J-SAFE3 and STSAFE-J platforms exposing a 3.0.4 Java Card API. It is exploitable for STSAFE-J in closed configuration and J-SIGN (when signature verification is activated) but not for J-SAFE3 EPASS BAC and EAC products. It might also impact other products based on the J-SAFE-3 Java Card platform.

Published: 2022-03-04 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-43392 is rated Low Risk (26.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-43392

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-04-06 0.05% 0.03% -0.02%
2 2023-03-07 0.89% 0.05% -0.83%
3 2022-03-05 0.89%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-43392

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.2 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.5 3.6 [email protected]
1.9 2.0 LOW
AV:L/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
3.4 2.9 [email protected]

Weakness enumeration for CVE-2021-43392

Affected software / configurations for CVE-2021-43392

Vendor Product Version Raw CPE
st j-safe3_firmware 1.2.5 cpe:2.3:o:st:j-safe3_firmware:1.2.5:*:*:*:*:*:*:*
st stsafe-j_firmware 1.1.4 cpe:2.3:o:st:stsafe-j_firmware:1.1.4:*:*:*:*:*:*:*

References for CVE-2021-43392

cvelogic Threat Intelligence