CVE-2021-42757 vulnerability in Fortinet Products
Published on December 8, 2021
A buffer overflow [CWE-121] in the TFTP client library of FortiOS before 6.4.7 and FortiOS 7.0.0 through 7.0.2, may allow an authenticated local attacker to achieve arbitrary code execution via specially crafted command line arguments.
Vulnerability Analysis
CVE-2021-42757 can be exploited with local system access, and requires user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.
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-2021-42757 has been classified to as a Classic Buffer Overflow vulnerability or weakness.
Products Associated with CVE-2021-42757
You can be notified by email with stack.watch whenever vulnerabilities like CVE-2021-42757 are published in these products:
Affected Versions
Fortinet FortiOS:- Version 7.0.0, <= 7.0.2 is affected.
- Version 6.4.0, <= 6.4.7 is affected.
- Version 6.2.0, <= 6.2.9 is affected.
- Version 6.0.0, <= 6.0.13 is affected.
- Version 5.6.0, <= 5.6.14 is affected.
- Version 5.4.0, <= 5.4.13 is affected.
- Version 5.2.0, <= 5.2.15 is affected.
- Version 5.0.0, <= 5.0.14 is affected.
- Version 6.4.0, <= 6.4.1 is affected.
- Version 6.3.0 is affected.
- Version 6.2.0, <= 6.2.2 is affected.
- Version 6.1.0, <= 6.1.4 is affected.
- Version 6.4.0, <= 6.4.4 is affected.
- Version 6.0.0, <= 6.0.10 is affected.
- Version 7.0.0, <= 7.0.1 is affected.
- Version 2.0.0, <= 2.0.7 is affected.
- Version 1.2.0, <= 1.2.13 is affected.
- Version 1.1.0, <= 1.1.6 is affected.
- Version 1.0.0, <= 1.0.7 is affected.
- Version 6.4.0, <= 6.4.2 is affected.
- Version 6.0.0, <= 6.0.10 is affected.
- Version 2.7.0, <= 2.7.7 is affected.
- Version 2.6.0, <= 2.6.3 is affected.
- Version 6.0.0, <= 6.0.10 is affected.
- Version 5.3.0, <= 5.3.8 is affected.
- Version 5.2.0, <= 5.2.6 is affected.
- Version 5.1.0, <= 5.1.2 is affected.
- Version 5.0.0, <= 5.0.3 is affected.
- Version 7.0.0, <= 7.0.2 is affected.
- Version 6.4.0, <= 6.4.6 is affected.
- Version 6.2.0, <= 6.2.7 is affected.
- Version 6.0.0, <= 6.0.12 is affected.
- Version 5.4.0, <= 5.4.12 is affected.
- Version 7.0.0, <= 7.0.2 is affected.
- Version 6.4.0, <= 6.4.7 is affected.
- Version 6.2.0, <= 6.2.13 is affected.
- Version 6.0.0, <= 6.0.12 is affected.
- Version 1.5.0, <= 1.5.2 is affected.
- Version 1.4.0 is affected.
- Version 1.3.0, <= 1.3.1 is affected.
- Version 1.2.0 is affected.
- Version 1.1.0 is affected.
- Version 5.5.0, <= 5.5.1 is affected.
- Version 5.4.0, <= 5.4.3 is affected.
- Version 5.3.0, <= 5.3.2 is affected.
- Version 5.2.0 is affected.
- Version 5.1.0 is affected.
- Version 5.0.0 is affected.
- Version 4.7.0 is affected.
- Version 4.6.0 is affected.
- Version 4.5.0 is affected.
- Version 4.4.0, <= 4.4.2 is affected.
- Version 7.0.0, <= 7.0.3 is affected.
- Version 6.4.0, <= 6.4.9 is affected.
- Version 6.2.0, <= 6.2.7 is affected.
- Version 6.0.0, <= 6.0.7 is affected.
- Version 6.2.0, <= 6.2.2 is affected.
- Version 6.1.0, <= 6.1.5 is affected.
- Version 6.0.0, <= 6.0.4 is affected.
- Version 5.4.0, <= 5.4.5 is affected.
- Version 5.3.0, <= 5.3.7 is affected.
- Version 5.2.0, <= 5.2.8 is affected.
- Version 5.1.0, <= 5.1.7 is affected.
- Version 5.0.0, <= 5.0.4 is affected.
- Version 6.4.0, <= 6.4.1 is affected.
- Version 6.3.0, <= 6.3.16 is affected.
- Version 6.2.0, <= 6.2.8 is affected.
- Version 6.1.0, <= 6.1.4 is affected.
- Version 6.0.0, <= 6.0.8 is affected.
- Version 5.9.0, <= 5.9.2 is affected.
- Version 5.8.5, <= 5.8.7 is affected.
- Version 5.8.0, <= 5.8.3 is affected.
- Version 5.7.0, <= 5.7.3 is affected.
- Version 5.6.0, <= 5.6.2 is affected.
- Version 5.5.0, <= 5.5.7 is affected.
- Version 5.4.0, <= 5.4.1 is affected.
- Version 5.3.0, <= 5.3.9 is affected.
- Version 5.2.0, <= 5.2.4 is affected.
- Version 5.1.0, <= 5.1.4 is affected.
- Version 5.0.0, <= 5.0.6 is affected.
- Version 7.0.0, <= 7.0.2 is affected.
- Version 6.4.0, <= 6.4.7 is affected.
- Version 6.2.0, <= 6.2.13 is affected.
- Version 6.0.0, <= 6.0.12 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.