CVE-2021-34595 : What You Need to Know
Learn about CVE-2021-34595 impacting CODESYS V2, causing a denial-of-service issue. Understand the vulnerability, affected versions, and mitigation steps.
A crafted request with invalid offsets may cause an out-of-bounds read or write access in CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56, resulting in a denial-of-service condition or local memory overwrite.
Understanding CVE-2021-34595
This CVE describes a vulnerability in CODESYS V2 that could potentially lead to a denial-of-service condition due to an out-of-bounds read or write access.
What is CVE-2021-34595?
CVE-2021-34595 highlights a security issue in CODESYS V2 that could be exploited by sending a specially crafted request with invalid offsets, impacting the Runtime Toolkit and PLCWinNT versions prior to V2.4.7.56.
The Impact of CVE-2021-34595
The vulnerability can result in a denial-of-service condition or local memory overwrite, potentially affecting the availability and integrity of the affected systems.
Technical Details of CVE-2021-34595
This section provides more detailed technical insights into the vulnerability.
Vulnerability Description
The vulnerability stems from improper handling of requests with invalid offsets, leading to out-of-bounds read or write access within CODESYS V2.
Affected Systems and Versions
CODESYS V2 versions less than V2.4.7.56 are affected, particularly the Runtime Toolkit 32 bit full and the PLCWinNT products.
Exploitation Mechanism
The exploitation requires crafting requests with specific offsets to trigger the out-of-bounds access, potentially causing denial-of-service or local memory overwrite.
Mitigation and Prevention
To address the CVE-2021-34595 vulnerability, consider the following mitigation strategies.
Immediate Steps to Take
CODESYS GmbH has released updates to resolve the vulnerability issue. Ensure you update the affected products to the following versions:
- CODESYS Runtime Toolkit 32 bit full version V2.4.7.56
- CODESYS PLCWinNT version V2.4.7.56, included in CODESYS Development System setup version V2.3.9.68.
Long-Term Security Practices
Implement secure coding practices, regularly update software, and monitor for any anomalous activities that could indicate exploitation attempts.
Patching and Updates
Stay informed about security patches and updates from CODESYS GmbH. Apply patches promptly and maintain a proactive approach to system security.