CVE-2021-34561 Explained : Impact and Mitigation
Discover the details of CVE-2021-34561, a critical vulnerability in WirelessHART-Gateway versions up to 3.0.8 that allows bypassing IP or firewall access restrictions via DNS rebinding. Learn about the impact, affected systems, and mitigation strategies.
A vulnerability in WirelessHART-Gateway <= 3.0.8 allows attackers to bypass IP or firewall access restrictions through DNS rebinding. This vulnerability was reported by Pepperl+Fuchs.
Understanding CVE-2021-34561
This CVE identifies a critical issue in WirelessHART-Gateway versions up to 3.0.8 that can be exploited by attackers to circumvent access restrictions using DNS rebinding.
What is CVE-2021-34561?
The vulnerability in WirelessHART-Gateway <= 3.0.8 enables threat actors to bypass IP or firewall-based access controls via DNS rebinding, allowing unauthorized access to systems.
The Impact of CVE-2021-34561
With a CVSS v3.1 base score of 7.5 (High Severity), this vulnerability poses a significant risk to confidentiality, integrity, and availability. The attack vector is through the network, with high complexity and impact on system availability.
Technical Details of CVE-2021-34561
This section provides further technical insights into the vulnerability.
Vulnerability Description
The issue arises in WirelessHART-Gateway <= 3.0.8 when the application lacks external accessibility or implements IP-based access controls. Attackers exploit DNS Rebinding to evade existing IP or firewall restrictions, leveraging the target's browser for proxy access.
Affected Systems and Versions
Phoenix Contact's products WHA-GW-F2D2-0-AS-Z2-ETH and WHA-GW-F2D2-0-AS-Z2-ETH.EIP version 3.0.8 are impacted by this vulnerability.
Exploitation Mechanism
Threat actors can exploit this vulnerability using DNS Rebinding to bypass IP or firewall-based access restrictions, gaining unauthorized access to networks.
Mitigation and Prevention
Understanding how to mitigate and prevent CVE-2021-34561 is crucial for safeguarding systems.
Immediate Steps to Take
Take external protective measures, restrict network exposure, isolate affected products, and utilize secure remote access methods like VPNs.
Long-Term Security Practices
Regularly update and patch affected systems, conduct security assessments, and implement network segmentation to enhance overall security.
Patching and Updates
At present, there are no available updates for addressing this vulnerability in WirelessHART-Gateway <= 3.0.8.