Weakness · Medium
CWE-481: Assigning instead of Comparing
What it is
The code uses an operator for assignment when the intention was to perform a comparison.
- Severity (our rating)
- Medium
- Likelihood of exploit
- Low
- Introduced during
- Implementation
- Exploited in the wild
- No CVE in CISA's catalog
In more detail
In many languages the compare statement is very close in appearance to the assignment statement and are often confused. This bug is generally the result of a typo and usually causes obvious problems with program execution. If the comparison is in an if statement, the if statement will usually evaluate the value of the right-hand side of the predicate.
What an attacker can do
- Alter Execution Logic (Other)
How to prevent it
Testing
- Many IDEs and static analysis products will detect this problem.
Implementation
- Place constants on the left. If one attempts to assign a constant with a variable, the compiler will produce an error.
How to find it
- Automated Static Analysis. Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.