CVE-2021-20046 Explained : Impact and Mitigation
Learn about CVE-2021-20046, a Stack-based buffer overflow vulnerability in SonicWall SonicOS firmware versions 5 to 7 that allows remote attackers to trigger DoS and potential code execution.
A Stack-based buffer overflow in the SonicOS HTTP Content-Length response header can lead to Denial of Service (DoS) and potential code execution. This vulnerability affects SonicOS Gen 5, Gen 6, and Gen 7 firmware versions.
Understanding CVE-2021-20046
This section dives into the details of the CVE-2021-20046 vulnerability.
What is CVE-2021-20046?
A Stack-based buffer overflow in the SonicOS HTTP Content-Length response header allows a remote authenticated attacker to cause Denial of Service (DoS) and potentially results in code execution in the firewall. This vulnerability affected SonicOS Gen 5, Gen 6, and Gen 7 firmware versions.
The Impact of CVE-2021-20046
The vulnerability can be exploited by a remote authenticated attacker to perform DoS attacks and potentially execute malicious code on the affected SonicOS devices.
Technical Details of CVE-2021-20046
In this section, the technical aspects of CVE-2021-20046 are discussed.
Vulnerability Description
The vulnerability stems from a Stack-based buffer overflow in the SonicOS HTTP Content-Length response header.
Affected Systems and Versions
SonicOS versions including 7.0.1-R146 and earlier, 7.0.1-5023-1349 and earlier, 7.0.1-5018-R1715 and earlier, 6.5.4.8-89n and earlier, 6.5.1.13-1n and earlier, 6.0.5.3-94o and earlier, 6.5.4.v_21s-1288 and earlier, and 5.9.1.13 and earlier are affected by this vulnerability.
Exploitation Mechanism
A remote authenticated attacker can exploit this vulnerability by manipulating the SonicOS HTTP Content-Length response header to trigger a buffer overflow and potentially execute arbitrary code.
Mitigation and Prevention
This section outlines the steps to mitigate and prevent exploitation of CVE-2021-20046.
Immediate Steps to Take
Users are advised to apply the latest security patches provided by SonicWall to fix the vulnerability. Additionally, restrict network access to the affected devices.
Long-Term Security Practices
In the long term, ensure regular security updates are applied, conduct security audits, and monitor network traffic for any suspicious activity on SonicOS devices.
Patching and Updates
Stay informed about security advisories from SonicWall and promptly apply patches to address known vulnerabilities in SonicOS firmware.