How severe is CVE-2021-27389?

CVE-2021-27389 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-27389 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27389?

CVE-2021-27389 primarily affects Siemens Opcenter Quality. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-27389?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-27389 published?

CVE-2021-27389 was published on 2021-04-22 and last updated on 2026-06-17.

CVE-2021-27389

CVE-2021-27389 is a critical-severity vulnerability in Siemens Opcenter Quality with a CVSS 3.x base score of 9.8. 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-321.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-321
Affected product: Siemens Opcenter Quality
Published: 2021-04-22
Last modified: 2026-06-17

Description

A vulnerability has been identified in Opcenter Quality (All versions < V12.2), QMS Automotive (All versions < V12.30). A private sign key is shipped with the product without adequate protection.

Frequently asked questions

What is CVE-2021-27389?: A vulnerability has been identified in Opcenter Quality (All versions < V12.2), QMS Automotive (All versions < V12.30). A private sign key is shipped with the product without adequate protection.
How severe is CVE-2021-27389?: CVE-2021-27389 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-27389 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27389?: CVE-2021-27389 primarily affects Siemens Opcenter Quality. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-27389?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-27389 published?: CVE-2021-27389 was published on 2021-04-22 and last updated on 2026-06-17.

References

https://cert-portal.siemens.com/productcert/pdf/ssa-788287.pdf

Affected products (2)

cpe:2.3:a:siemens:opcenter_quality:*:*:*:*:*:*:*:*
cpe:2.3:a:siemens:qms_automotive:*:*:*:*:*:*:*:*

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