CVE-2020-5138 : Security Advisory and Response
Learn about CVE-2020-5138, a Heap Overflow vulnerability in SonicOS allowing remote unauthenticated attackers to cause Denial of Service (DoS) and system crashes. Find mitigation steps here.
A Heap Overflow vulnerability in the SonicOS allows a remote unauthenticated attacker to cause Denial of Service (DoS) on the firewall SSLVPN service and leads to SonicOS crash. This vulnerability affected SonicOS Gen 5 version 5.9.1.7, 5.9.1.13, Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v, and Gen 7 version SonicOS 7.0.0.0.
Understanding CVE-2020-5138
A Heap Overflow vulnerability in SonicOS
What is CVE-2020-5138?
This vulnerability in SonicOS allows a remote unauthenticated attacker to trigger a Denial of Service (DoS) attack on the firewall SSLVPN service, potentially leading to a system crash.
The Impact of CVE-2020-5138
- Remote unauthenticated attackers can exploit the vulnerability to cause a DoS condition on the affected SonicOS versions.
- The security flaw may result in a system crash, disrupting normal operations.
Technical Details of CVE-2020-5138
A Heap Overflow vulnerability in SonicOS
Vulnerability Description
The vulnerability allows remote unauthenticated attackers to trigger a DoS attack on the firewall SSLVPN service, potentially causing a system crash.
Affected Systems and Versions
The following versions of SonicOS are affected:
- SonicOS 6.5.4.7-79n and earlier
- SonicOS 5.9.1.7-2n and earlier
- SonicOS 5.9.1.13-5n and earlier
- SonicOS 6.5.1.11-4n and earlier
- SonicOS 6.0.5.3-93o and earlier
- SonicOSv 6.5.4.4-44v-21-794 and earlier
- SonicOS 7.0.0.0-1
Exploitation Mechanism
The vulnerability can be exploited remotely by unauthenticated attackers to overload the firewall SSLVPN service, leading to a DoS condition and potential system crash.
Mitigation and Prevention
Steps to address the CVE-2020-5138 vulnerability
Immediate Steps to Take
- Apply the latest security patches provided by SonicWall for the affected SonicOS versions.
- Monitor network traffic for any suspicious activity that could indicate an ongoing attack.
Long-Term Security Practices
- Regularly update and patch all software and firmware to mitigate potential vulnerabilities.
- Implement network segmentation and access controls to limit the impact of potential attacks.
Patching and Updates
- Stay informed about security advisories from SonicWall and promptly apply recommended patches to secure the system against known vulnerabilities.