CVE-2020-5135 vulnerability in SonicWall Products
Published on October 12, 2020
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.
Known Exploited Vulnerability
This SonicWall SonicOS Buffer Overflow Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall.
The following remediation steps are recommended / required by April 5, 2022: Apply updates per vendor instructions.
Vulnerability Analysis
CVE-2020-5135 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors in an automatable fashion. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Weakness Type
What is a Classic Buffer Overflow Vulnerability?
The program copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. A buffer overflow condition exists when a program attempts to put more data in a buffer than it can hold, or when a program attempts to put data in a memory area outside of the boundaries of a buffer. The simplest type of error, and the most common cause of buffer overflows, is the "classic" case in which the program copies the buffer without restricting how much is copied. Other variants exist, but the existence of a classic overflow strongly suggests that the programmer is not considering even the most basic of security protections.
CVE-2020-5135 has been classified to as a Classic Buffer Overflow vulnerability or weakness.
Products Associated with CVE-2020-5135
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Affected Versions
SonicWall SonicOS:- Version SonicOS 6.5.4.7-79n and earlier is affected.
- Version SonicOS 6.5.1.11-4n and earlier is affected.
- Version SonicOS 6.0.5.3-93o and earlier is affected.
- Version SonicOSv 6.5.4.4-44v-21-794 and earlier is affected.
- Version SonicOS 7.0.0.0-1 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.