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.)
CWE-482 Variant Draft
Comparing instead of Assigning
This vulnerability occurs when a developer accidentally uses a comparison operator (like '==') where an assignment operator (like '=') was intended, creating a logic error instead of setting a value.
Definition
What is CWE-482?
This vulnerability occurs when a developer accidentally uses a comparison operator (like '==') where an assignment operator (like '=') was intended, creating a logic error instead of setting a value.
This common coding mistake happens because assignment and comparison operators look very similar in many programming languages. For example, using `if (x = 5)` instead of `if (x == 5)` assigns the value 5 to `x` and then evaluates the assignment's result as the condition, which is often always true, breaking the intended program logic.
To prevent this, developers should adopt defensive coding habits like placing constants on the left side in comparisons (e.g., `if (5 == x)`), which would cause a compilation error if written incorrectly as `if (5 = x)`. Modern compilers and linters often flag this pattern with warnings like "possible unintended assignment," which should always be investigated and corrected.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-482
Bisher sind in MITREs Katalog keine öffentlichen CVE-Referenzen mit dieser CWE verknüpft.
Wie Angreifer es ausnutzen
Angreiferpfad Schritt für Schritt
- 1
The following example demonstrates the weakness.
- 2
The following C/C++ example shows a simple implementation of a stack that includes methods for adding and removing integer values from the stack. The example uses pointers to add and remove integer values to the stack array variable.
- 3
The push method includes an expression to assign the integer value to the location in the stack pointed to by the pointer variable.
- 4
However, this expression uses the comparison operator "==" rather than the assignment operator "=". The result of using the comparison operator instead of the assignment operator causes erroneous values to be entered into the stack and can cause unexpected results.
Verwundbares Codebeispiel
Vulnerable Java
The following example demonstrates the weakness.
void called(int foo) {
foo==1;
if (foo==1) System.out.println("foo\n");
}
int main() {
called(2);
return 0;
} Sicheres Codebeispiel
Secure pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
const safe = validateAndEscape(input);
return executeWithGuards(safe);
} What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Präventions-Checkliste
How to prevent CWE-482
- Testing Many IDEs and static analysis products will detect this problem.
Erkennungssignale
How to detect CWE-482
CWE-482
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Häufig gestellte Fragen Was ist CWE-482?
Wie gravierend ist CWE-482?
Welche Sprachen oder Plattformen sind von CWE-482 betroffen?
Wie kann ich CWE-482 verhindern?
Wie erkennt und behebt Plexicus CWE-482?
Wo erfahre ich mehr über CWE-482?
Frequently asked questions
Was ist CWE-482?
This vulnerability occurs when a developer accidentally uses a comparison operator (like '==') where an assignment operator (like '=') was intended, creating a logic error instead of setting a value.
Wie gravierend ist CWE-482?
MITRE stuft die Exploit-Wahrscheinlichkeit als niedrig ein — eine Ausnutzung ist selten, die Schwachstelle sollte aber dennoch behoben werden, sobald sie entdeckt wird.
Welche Sprachen oder Plattformen sind von CWE-482 betroffen?
MITRE lists the following affected platforms: C, C++.
Wie kann ich CWE-482 verhindern?
Many IDEs and static analysis products will detect this problem.
Wie erkennt und behebt Plexicus CWE-482?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-482 bei jedem Commit. Bei einem Treffer öffnet unser Codex-Remedium-Agent einen Fix-PR mit korrigiertem Code, Tests und einer einzeiligen Zusammenfassung für den Reviewer.
Wo erfahre ich mehr über CWE-482?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/482.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-482
CWE-480 Parent
Use of Incorrect Operator
This vulnerability occurs when a developer mistakenly uses the wrong operator in their code, leading to unintended and potentially…
CWE-481 Sibling
Assigning instead of Comparing
This flaw occurs when a developer accidentally uses the assignment operator (=) instead of the comparison operator (== or ===). The code…
CWE-597 Sibling
Use of Wrong Operator in String Comparison
This vulnerability occurs when a developer incorrectly compares string values, typically by using reference equality operators (like == or…
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Bereit zu validieren, was zählt.
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