The product accidentally uses the wrong operator, which changes the logic in security-relevant ways.
View on MITREThese types of errors are generally the result of a typo by the programmer.
This weakness can cause unintended logic to be executed and other unexpected application behavior.
No mitigation information available for this CWE.
This weakness can be found easily using static analysis. However in some cases an operator might appear to be incorrect, but is actually correct and reflects unusual logic within the program.
This weakness can be found easily using static analysis. However in some cases an operator might appear to be incorrect, but is actually correct and reflects unusual logic within the program.
The following C/C++ and C# examples attempt to validate an int input parameter against the integer value 100.
However, the expression to be evaluated in the if statement uses the assignment operator "=" rather than the comparison operator "==". The result of using the assignment operator instead of the comparison operator causes the int variable to be reassigned locally and the expression in the if statement will always evaluate to the value on the right hand side of the expression. This will result in the input value not being properly validated, which can cause unexpected results.
int isValid(int value) {if (value=100) {printf("Value is valid\n");return(1);}printf("Value is not valid\n");return(0);}The following C/C++ and C# examples attempt to validate an int input parameter against the integer value 100.
However, the expression to be evaluated in the if statement uses the assignment operator "=" rather than the comparison operator "==". The result of using the assignment operator instead of the comparison operator causes the int variable to be reassigned locally and the expression in the if statement will always evaluate to the value on the right hand side of the expression. This will result in the input value not being properly validated, which can cause unexpected results.
bool isValid(int value) {if (value=100) {Console.WriteLine("Value is valid.");return true;}Console.WriteLine("Value is not valid.");return false;}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.
The push method includes an expression to assign the integer value to the location in the stack pointed to by the pointer variable.
#define SIZE 50int *tos, *p1, stack[SIZE]; void push(int i) { p1++;if(p1==(tos+SIZE)) { // Print stack overflow error message and exit }*p1 == i; } int pop(void) { if(p1==tos) { // Print stack underflow error message and exit }p1--;return *(p1+1); } int main(int argc, char *argv[]) { // initialize tos and p1 to point to the top of stack tos = stack;p1 = stack; // code to add and remove items from stack ...return 0; }The example code below is taken from the CVA6 processor core of the HACK@DAC'21 buggy OpenPiton SoC. Debug access allows users to access internal hardware registers that are otherwise not exposed for user access or restricted access through access control protocols. Hence, requests to enter debug mode are checked and authorized only if the processor has sufficient privileges. In addition, debug accesses are also locked behind password checkers. Thus, the processor enters debug mode only when the privilege level requirement is met, and the correct debug password is provided.
The following code [REF-1377] illustrates an instance of a vulnerable implementation of debug mode. The core correctly checks if the debug requests have sufficient privileges and enables the debug_mode_d and debug_mode_q signals. It also correctly checks for debug password and enables umode_i signal.
module csr_regfile #( ... // check that we actually want to enter debug depending on the privilege level we are currently in unique case (priv_lvl_o) riscv::PRIV_LVL_M: begin debug_mode_d = dcsr_q.ebreakm; ... riscv::PRIV_LVL_U: begin debug_mode_d = dcsr_q.ebreaku; ... assign priv_lvl_o = (debug_mode_q || umode_i) ? riscv::PRIV_LVL_M : priv_lvl_q; ... debug_mode_q <= debug_mode_d; ...The example code below is taken from the CVA6 processor core of the HACK@DAC'21 buggy OpenPiton SoC. Debug access allows users to access internal hardware registers that are otherwise not exposed for user access or restricted access through access control protocols. Hence, requests to enter debug mode are checked and authorized only if the processor has sufficient privileges. In addition, debug accesses are also locked behind password checkers. Thus, the processor enters debug mode only when the privilege level requirement is met, and the correct debug password is provided.
The following code [REF-1377] illustrates an instance of a vulnerable implementation of debug mode. The core correctly checks if the debug requests have sufficient privileges and enables the debug_mode_d and debug_mode_q signals. It also correctly checks for debug password and enables umode_i signal.
module csr_regfile #( ... // check that we actually want to enter debug depending on the privilege level we are currently in unique case (priv_lvl_o) riscv::PRIV_LVL_M: begin debug_mode_d = dcsr_q.ebreakm; ... riscv::PRIV_LVL_U: begin debug_mode_d = dcsr_q.ebreaku; ... assign priv_lvl_o = (debug_mode_q && umode_i) ? riscv::PRIV_LVL_M : priv_lvl_q; ... debug_mode_q <= debug_mode_d; ...Chain: data visualization program written in PHP uses the "!=" operator instead of the type-strict "!==" operator (CWE-480) when validating hash values, potentially leading to an incorrect type conversion (CWE-704)
View DetailsChain: Python-based HTTP Proxy server uses the wrong boolean operators (CWE-480) causing an incorrect comparison (CWE-697) that identifies an authN failure if all three conditions are met instead of only one, allowing bypass of the proxy authentication (CWE-1390)
View DetailsAdditional facts reviewed against primary or authoritative security sources.
Documented detection approaches include Automated Static Analysis, and Manual Static Analysis; recorded impacts include Alter Execution Logic; observed examples include CVE-2022-3979, and CVE-2021-3116. Use these source-defined anchors to turn CWE-480 into implementation, review, and verification checks for the affected component.
CWE-480: Use of Incorrect Operator — MITRE CWEUse NIST SSDF practices to make prevention of CWE-480, Use of Incorrect Operator, an explicit development outcome. Translate the CWE definition into security requirements and design constraints, choose safer implementation patterns and toolchain checks, and define acceptance evidence before release. Feed every confirmed occurrence back into the requirements, design review, and coding rules so the same root cause is removed across the product rather than patched in one location.
NIST SP 800-218 Secure Software Development Framework — National Institute of Standards and TechnologyUse CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-480, Use of Incorrect Operator, has evidence of exploitation in the wild. Confirm the CVE-to-CWE root-cause mapping independently before attaching the example, then capture the affected product, required action, and remediation deadline. A missing KEV match is not evidence that the weakness is unexploited, and a KEV entry must not be generalized to every occurrence of this CWE.
Known Exploited Vulnerabilities Catalog — Cybersecurity and Infrastructure Security AgencyApply MITRE's full root-cause mapping guidance when using CWE-480, Use of Incorrect Operator. Separate weakness language from attacker prerequisites and technical impact, check the entry's abstraction and vulnerability-mapping notes, and prefer the most specific Base or Variant supported by the evidence. Record the rejected alternatives and require an independent review before the mapping is used for remediation trends or program metrics.
CVE to CWE Root Cause Mapping Guidance — MITRE CWEApply MITRE's root-cause mapping quick tips to CWE-480, Use of Incorrect Operator. Confirm the finding describes the causal weakness rather than an impact or attack pattern, compare the abstraction and mapping notes with plausible alternatives, and have a second reviewer challenge the selection. Preserve the evidence and reasoning so recurring defects can be measured against one consistent identifier.
CVE to CWE Root Cause Mapping Quick Tips — MITRE CWECWE-480: Use of Incorrect Operator is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product accidentally uses the wrong operator, which changes the logic in security-relevant ways. These types of errors are generally the result of a typo by the programmer.
If exploited, CWE-480 (Use of Incorrect Operator) it can compromise Other, leading to outcomes such as Alter Execution Logic.
CWE-480 can be detected using Automated Static Analysis and Manual Static Analysis. Combining automated tooling with manual review typically yields the best coverage.
CWE-480 commonly affects C, C++, Perl and Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
MITRE documents real CVEs mapped to CWE-480, including CVE-2022-3979 and CVE-2021-3116. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.
A CWE (Common Weakness Enumeration) like CWE-480 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.