CVE-2021-21001 Explained : Impact and Mitigation
Learn about CVE-2021-21001, a critical vulnerability in WAGO PFC200 devices allowing unauthorized access to the file system with elevated privileges. Find mitigation steps and recommendations here.
This article discusses a critical vulnerability identified as CVE-2021-21001 in WAGO PFC200 devices. An attacker with network access can exploit this vulnerability to access the file system with elevated privileges.
Understanding CVE-2021-20657
This section delves into the details of the CVE-2021-21001 vulnerability.
What is CVE-2021-20657?
The CVE-2021-21001 vulnerability affects WAGO PFC200 devices running various firmware versions. It allows an authorized attacker to gain access to the file system with higher privileges by sending specially crafted packets.
The Impact of CVE-2021-20657
The impact of this vulnerability is significant, with a base severity score of 9.1 (Critical) according to CVSS v3.1. It poses high risks to confidentiality, integrity, and availability of the affected systems.
Technical Details of CVE-2021-20657
Here are the technical specifics related to CVE-2021-21001.
Vulnerability Description
The vulnerability, categorized as CWE-22, results from improper limitation of a pathname to a restricted directory, allowing path traversal attacks on the target systems.
Affected Systems and Versions
The Series PFC200 Controller and Series Ethernet Controller from WAGO are impacted by CVE-2021-21001. Specific firmware versions and product details are provided in the advisory.
Exploitation Mechanism
This vulnerability can be exploited by sending specially crafted packets to the targeted WAGO PFC200 devices, enabling unauthorized access to the file system with elevated privileges.
Mitigation and Prevention
To mitigate the risks associated with CVE-2021-21001, follow these preventive measures.
Immediate Steps to Take
Utilize best security practices to safeguard systems from local and network-based attacks. Restrict untrusted network access to the devices and follow specific guidelines provided in the solution section.
Long-Term Security Practices
Implement a robust security posture by regularly updating systems, conducting security audits, and enhancing network security measures.
Patching and Updates
WAGO recommends affected users with CODESYS 2.3 Runtime PLCs to upgrade to the specified firmware versions available in the provided solution link.