CVE-2021-20027 is a vulnerability in SonicWall Sonicos
Published on June 14, 2021
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause a Denial of Service (DoS) by sending a specially crafted request. This vulnerability affects SonicOS Gen5, Gen6, Gen7 platforms, and SonicOSv virtual firewalls.
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-2021-20027 has been classified to as a Classic Buffer Overflow vulnerability or weakness.
Products Associated with CVE-2021-20027
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Affected Versions
SonicWall SonicOS:- Version SonicOS 5.9.1.13 and earlier is affected.
- Version SonicOSv 6.5.4.4 and earlier is affected.
- Version SonicOS 6.0.5.3 and earlier is affected.
- Version SonicOS 6.5.1.12 and earlier is affected.
- Version SonicOS 6.5.4.7 and earlier is affected.
- Version SonicOS 7.0.1-R1219 and earlier is affected.
- Version SonicOS 7.0.1-R514 and earlier is affected.
- Version SonicOS 7.0.1-R1262 and earlier 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.