CVE-2021-3031 Explained : Impact and Mitigation
Learn about CVE-2021-3031, a vulnerability in Palo Alto Networks' PAN-OS allowing information exposure due to improper clearance of padding bytes in Ethernet packets. Find details, impact, affected versions, mitigation, and solutions.
CVE-2021-3031, published on January 13, 2021, involves an information exposure vulnerability in Palo Alto Networks' PAN-OS. It allows an attacker on the same Ethernet subnet to gather potentially sensitive information due to padding bytes in Ethernet packets not being cleared properly.
Understanding CVE-2021-3031
This section delves into the details of the CVE-2021-3031 vulnerability.
What is CVE-2021-3031?
The vulnerability in PAN-OS exposes a small amount of firewall memory data into Ethernet packets due to incomplete clearance of padding bytes. This could allow an attacker within the same Ethernet subnet to extract sensitive information.
The Impact of CVE-2021-3031
The vulnerability, also known as Etherleak, affects PAN-OS versions earlier than 8.1.18, 9.0.12, and 9.1.5. It has a CVSS base score of 4.3, indicating a medium severity issue with low confidentiality impact.
Technical Details of CVE-2021-3031
This section outlines the technical aspects of the CVE-2021-3031 vulnerability.
Vulnerability Description
Padding bytes are not adequately cleared from Ethernet packets, leading to leakage of firewall memory data into the packets.
Affected Systems and Versions
The affected systems include PA-200, PA-220, PA-500, PA-800, PA-2000 Series, PA-3000 Series, PA-3200 Series, and PA-5200 firewalls running PAN-OS versions earlier than 8.1.18, 9.0.12, and 9.1.5.
Exploitation Mechanism
While the vulnerability can leak potentially sensitive information, Palo Alto Networks has not detected any malicious exploitation of this issue.
Mitigation and Prevention
This section provides insights into mitigating the impact of CVE-2021-3031.
Immediate Steps to Take
Unfortunately, there is no workaround to prevent the information leak in Ethernet packets. However, restricting access to networks can reduce the risk associated with this vulnerability.
Long-Term Security Practices
Implementing network segmentation and access controls can enhance security posture and prevent unauthorized access to sensitive information.
Patching and Updates
Palo Alto Networks has addressed this issue in PAN-OS 8.1.18, 9.0.12, 9.1.5, and all later versions.