CVE-2021-33542

Name: CVE-2021-33542
Creator: NVD / NIST
Published: 2021-06-25T19:15:09.817+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7/10EPSS 1.76%

Last modified Jun 17, 2026

CVE-2021-33542 is a high-severity vulnerability rated 7/10 on the CVSS scale. Phoenix Contact Classic Automation Worx Software Suite in Version 1.87 and below is affected by a remote code execution vulnerability. Manipulated PC Worx or Config+ projects could lead to a remote code execution when unallocated memory is freed because of incompletely initialized data. EPSS estimates a 1.76% chance of exploitation in the next 30 days.

Description

Phoenix Contact Classic Automation Worx Software Suite in Version 1.87 and below is affected by a remote code execution vulnerability. Manipulated PC Worx or Config+ projects could lead to a remote code execution when unallocated memory is freed because of incompletely initialized data. The attacker needs to get access to an original bus configuration file (*.bcp) to be able to manipulate data inside. After manipulation the attacker needs to exchange the original file by the manipulated one on the application programming workstation. Availability, integrity, or confidentiality of an application programming workstation might be compromised by attacks using these vulnerabilities. Automated systems in operation which were programmed with one of the above-mentioned products are not affected.

Metrics

CVSS 3.1

7/10

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

1.76%

75.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Phoenixcontact	Config\+	<= 1.87
Phoenixcontact	Pc Worx	<= 1.87
Phoenixcontact	Pc Worx Express	<= 1.87

References

https://cert.vde.com/en-us/advisories/vde-2021-020Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-782/Third Party Advisory, VDB Entry
https://cert.vde.com/en-us/advisories/vde-2021-020Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-782/Third Party Advisory, VDB Entry

Timeline

Published: Jun 25, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33542?

How severe is CVE-2021-33542?

CVE-2021-33542 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 1.76% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33542?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-33542?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST