How severe is CVE-2021-33716?

CVE-2021-33716 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-33716 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33716?

CVE-2021-33716 primarily affects Siemens Simatic Cp 1543-1 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-2021-33716?

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

When was CVE-2021-33716 published?

CVE-2021-33716 was published on 2021-09-14 and last updated on 2026-06-17.

CVE-2021-33716

CVE-2021-33716 is a medium-severity vulnerability in Siemens Simatic Cp 1543-1 Firmware with a CVSS 3.x base score of 6.5. 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-312.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 3.3
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-312
Affected product: Siemens Simatic Cp 1543-1 Firmware
Published: 2021-09-14
Last modified: 2026-06-17

Description

A vulnerability has been identified in SIMATIC CP 1543-1 (incl. SIPLUS variants) (All versions < V3.0), SIMATIC CP 1545-1 (All versions < V1.1). An attacker with access to the subnet of the affected device could retrieve sensitive information stored in cleartext.

Frequently asked questions

What is CVE-2021-33716?: A vulnerability has been identified in SIMATIC CP 1543-1 (incl. SIPLUS variants) (All versions < V3.0), SIMATIC CP 1545-1 (All versions < V1.1). An attacker with access to the subnet of the affected device could retrieve sensitive information stored in cleartext.
How severe is CVE-2021-33716?: CVE-2021-33716 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-33716 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33716?: CVE-2021-33716 primarily affects Siemens Simatic Cp 1543-1 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-2021-33716?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-33716 published?: CVE-2021-33716 was published on 2021-09-14 and last updated on 2026-06-17.

References

https://cert-portal.siemens.com/productcert/pdf/ssa-535997.pdf

Affected products (2)

cpe:2.3:o:siemens:simatic_cp_1543-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_cp_1545-1_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Siemens Simatic Cp 1543-1 Firmware

CVE-2022-34819 — Critical (CVSS 10.0): A vulnerability has been identified in SIMATIC CP 1242-7 V2 (All versions < V3.3.46), SIMATIC CP 1243-1 (All versions <…
CVE-2019-12815 — Critical (CVSS 9.8): An arbitrary file copy vulnerability in mod_copy in ProFTPD up to 1.3.5b allows for remote code execution and…
CVE-2022-34820 — High (CVSS 8.4): A vulnerability has been identified in SIMATIC CP 1242-7 V2 (All versions < V3.3.46), SIMATIC CP 1243-1 (All versions <…
CVE-2022-34821 — High (CVSS 7.6): A vulnerability has been identified in RUGGEDCOM RM1224 LTE(4G) EU (6GK6108-4AM00-2BA2), RUGGEDCOM RM1224 LTE(4G) NAM…
CVE-2024-50310 — High (CVSS 7.5): A vulnerability has been identified in SIMATIC CP 1543-1 V4.0 (6GK7543-1AX10-0XE0) (All versions >= V4.0.44 < V4.0.50).…
CVE-2016-8562 — High (CVSS 7.5): A vulnerability has been identified in SIMATIC CP 1543-1 (All versions < V2.0.28), SIPLUS NET CP 1543-1 (All versions <…

All CVEs affecting Siemens Simatic Cp 1543-1 Firmware →

Other CWE-312 (Cleartext Storage of Sensitive Information) vulnerabilities

CVE-2022-43757 — Critical (CVSS 9.9): A Cleartext Storage of Sensitive Information vulnerability in SUSE Rancher allows users on managed clusters to gain…
CVE-2021-36782 — Critical (CVSS 9.9): A Cleartext Storage of Sensitive Information vulnerability in SUSE Rancher allows authenticated Cluster Owners, Cluster…
CVE-2020-9045 — Critical (CVSS 9.9): During installation or upgrade to Software House C•CURE 9000 v2.70 and American Dynamics victor Video Management…
CVE-2026-31848 — Critical (CVSS 9.8): Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 uses the ecos_pw cookie for authentication, which…
CVE-2025-65826 — Critical (CVSS 9.8): The mobile application was found to contain stored credentials for the network it was developed on. If an attacker…
CVE-2025-34206 — Critical (CVSS 9.8): Vasion Print (formerly PrinterLogic) Virtual Appliance Host and Application (VA and SaaS deployments) mount host…

Browse all CWE-312 (Cleartext Storage of Sensitive Information) vulnerabilities →