How severe is CVE-2021-40364?

CVE-2021-40364 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-40364 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40364?

CVE-2021-40364 primarily affects Siemens Simatic Pcs 7. In total, 20 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-40364?

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

When was CVE-2021-40364 published?

CVE-2021-40364 was published on 2021-11-09 and last updated on 2026-06-17.

CVE-2021-40364

CVE-2021-40364 is a medium-severity vulnerability in Siemens Simatic Pcs 7 with a CVSS 3.x base score of 5.5. 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-532.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 2.1
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-532
Affected product: Siemens Simatic Pcs 7
Published: 2021-11-09
Last modified: 2026-06-17

Description

A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). The affected systems store sensitive information in log files. An attacker with access to the log files could publicly expose the information or reuse it to develop further attacks on the system.

Frequently asked questions

What is CVE-2021-40364?: A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). The affected systems store sensitive information in log files. An attacker with access to the log files could publicly expose the information or reuse it to develop further attacks on the system.
How severe is CVE-2021-40364?: CVE-2021-40364 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-40364 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40364?: CVE-2021-40364 primarily affects Siemens Simatic Pcs 7. In total, 20 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-40364?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-40364 published?: CVE-2021-40364 was published on 2021-11-09 and last updated on 2026-06-17.

References

https://cert-portal.siemens.com/productcert/pdf/ssa-840188.pdf

Affected products (20)

cpe:2.3:a:siemens:simatic_pcs_7:*:*:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_pcs_7:9.1:-:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:*:*:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:7.5:-:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:7.5:sp1:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:7.5:sp1_update1:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:7.5:sp1_update2:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:7.5:sp2:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:7.5:sp2_update1:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:7.5:sp2_update2:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:7.5:sp2_update3:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:7.5:sp2_update4:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:15:*:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:16:-:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:16:update1:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:16:update2:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:16:update3:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:16:update4:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:17:-:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_wincc:17:update1:*:*:*:*:*:*

More vulnerabilities in Siemens Simatic Pcs 7

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CVE-2019-10918 — High (CVSS 8.8): A vulnerability has been identified in SIMATIC PCS 7 V8.0 and earlier (All versions), SIMATIC PCS 7 V8.1 (All versions…

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