Resolve vulnerability: Divide a number by zero (!1) · Merge requests · extra-group / SAST

MR created from vulnerability: Divide a number by zero

AI GENERATED FIX

The suggested code changes were generated by GitLab Duo Vulnerability Resolution, an AI feature. Use this feature with caution. Before you run a pipeline or apply the code changes, carefully review and test them, to ensure that they solve the vulnerability.

The large language model that generated the suggested code changes was provided with the entire file that contains the vulnerable lines of code. It is not aware of any functionality outside of this context.

Please see our documentation for more information about this feature and leave feedback in this issue.

Description:

A ZeroDivisionError exception has been detected, this occurs when an arithmetic operation attempts to divide a number by zero. This can happen in various contexts, such as processing user inputs, performing calculations with variables, or working with data from external sources. Such errors not only disrupt the normal flow of the application but also can be exploited in certain scenarios to cause harm (eg. possible dos) or extract information based on the application's response to the error.

To prevent ZeroDivisionError exceptions and ensure application robustness:

Error handling: Implement error handling around division operations to catch and manage ZeroDivisionError gracefully.
Validation: Always validate inputs that are used in division operations to ensure they are not zero or unexpected values.

Severity: low
Location: rails5/lib/a_lib.rb:12

Analysis:

Analysis

The reported vulnerability is a "Divide a number by zero" issue, which is classified as CWE-369. This type of vulnerability can lead to unexpected behavior, crashes, or even security issues if not handled properly.

Upon reviewing the source code, the specific part of the code that is flagged as vulnerable is:

z = x / y # warns

This line of code is indeed vulnerable to a division by zero error, as the value of y is calculated as x - 100, which can result in a zero value if x is equal to 100.

However, in the context of this code, the division by zero error is not a security concern. The code is not handling user-input data or performing any sensitive operations that could be exploited by an attacker. The error is more of a programming error that can be fixed to improve the robustness of the code.

Therefore, this vulnerability is not a false positive, but rather a legitimate issue that needs to be addressed.

Fix

To fix this issue, we can add a simple check to ensure that the divisor is not zero before performing the division:

x = 100
y = x - 100
if y != 0
  z = x / y
else
  # Handle the case where y is zero
  z = nil # or some other default value
end

By adding this check, we can prevent the division by zero error and ensure that the code behaves as expected.

Summary:

Summary

To fix this issue, we added a simple check to ensure that the divisor is not zero before performing the division. This check prevents the division by zero error and ensures that the code behaves as expected.

The fix is:

if y != 0
  z = x / y
else
  # Handle the case where y is zero
  z = nil # or some other default value
end

By adding this check, we can prevent the division by zero error and ensure that the code is more robust and reliable.

Identifiers:

CWE-369
A6:2017 - Security Misconfiguration
Brakeman Warning Code 104
brakeman.ruby_error_rule-DivideByZero
A04:2021 - Insecure Design

Resolve vulnerability: Divide a number by zero