How severe is CVE-2021-43393?

CVE-2021-43393 has a CVSS 3.x base score of 6.2, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-43393 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43393?

CVE-2021-43393 primarily affects St Stsafe-j Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-43393?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-43393 published?

CVE-2021-43393 was published on 2022-03-04 and last updated on 2026-06-17.

CVE-2021-43393

CVE-2021-43393 is a medium-severity vulnerability in St Stsafe-j Firmware with a CVSS 3.x base score of 6.2. 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-347.

Key facts

Severity: Medium (CVSS 3.x base score 6.2)
CVSS v2: 1.9
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: St Stsafe-j Firmware
Published: 2022-03-04
Last modified: 2026-06-17

Description

STMicroelectronics STSAFE-J 1.1.4, J-SAFE3 1.2.5, and J-SIGN sometimes allow attackers to abuse signature verification. 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.

Frequently asked questions

What is CVE-2021-43393?: STMicroelectronics STSAFE-J 1.1.4, J-SAFE3 1.2.5, and J-SIGN sometimes allow attackers to abuse signature verification. 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.
How severe is CVE-2021-43393?: CVE-2021-43393 has a CVSS 3.x base score of 6.2, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-43393 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43393?: CVE-2021-43393 primarily affects St Stsafe-j Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-43393?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-43393 published?: CVE-2021-43393 was published on 2022-03-04 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:st:stsafe-j_firmware:1.1.4:*:*:*:*:*:*:*
cpe:2.3:o:st:j-safe3_firmware:1.2.5:*:*:*:*:*:*:*

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CVE-2021-43392 — Medium (CVSS 6.2): STMicroelectronics STSAFE-J 1.1.4, J-SAFE3 1.2.5, and J-SIGN sometimes allow attackers to obtain information on…

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