Page History

Division and modulo remainder operations performed on integers are susceptible to divide-by-zero errors. Consequently, the divisor in a division or remainder operation on integer types must be checked for zero prior to the operation. Division and remainder operations performed on floating-point numbers are not subject to this rule.

Noncompliant Code Example (Division)

The result of the / operator is the quotient from the division of the first arithmetic operand by the second arithmetic operand. Division operations are susceptible to divide-by-zero errors. Overflow can also occur during two's-complement signed integer division when the dividend is equal to the minimum (negative) value for the signed integer type and the divisor is equal to —1 −1 (see NUM00-J. Detect or prevent integer overflow for more information).

Noncompliant Code Example

This noncompliant code example can result in a divide-by-zero error during the division of the signed operands sl1 num1 and sl2. num2:

signed long sl1num1, sl2num2, result;

/* Initialize sl1num1 and sl2num2 */

result = sl1num1 / sl2num2;

Compliant Solution (Division)

This compliant solution tests the suspect division operation divisor to guarantee there is no possibility of divide-by-zero errors.:

signed long sl1num1, sl2num2, result;

/* Initialize sl1num1 and sl2num2 */

if (num2 (sl2 == 0) ) {
  /*/ handleHandle error condition */
}
 else {
  result = sl1num1 / sl2num2;
}

...

Noncompliant Code Example (Remainder)

The % operator provides the remainder when two operands of integer type are divided.

Noncompliant Code Example

This noncompliant code example can result in a divide-by-zero error during the remainder operation on the signed operands sl1 num1 and sl2. num2:

signed long sl1num1, sl2num2, result;

/* Initialize sl1num1 and sl2num2 */

result = sl1num1 % sl2num2;

Compliant Solution (Remainder)

This compliant solution tests the suspect remainder operation divisor to guarantee there is no possibility of a divide-by-zero error.:

signed long sl1num1, sl2num2, result;

/* Initialize sl1num1 and sl2num2 */

if (num2 (sl2 == 0 ) ) {
  //* handleHandle error condition */
}
 else {
  result = sl1num1 % sl2num2;
}

Risk Assessment

A divide division or remainder by zero can result in abnormal program termination and denial-of-service (DoS).

Automated Detection

...

Automated detection exists for C and C++, but not for Java yet.

Related Vulnerabilities

Search for vulnerabilities resulting from the violation of this rule on the CERT website.

Other Languages

...

Tool	Version	Checker	Description
Coverity	7.5	DIVIDE_BY_ZERO	Implemented
Parasoft Jtest	Include Page Parasoft_V Parasoft_V	CERT.NUM02.ZERO	Avoid division by zero
PVS-Studio	Include Page PVS-Studio_V PVS-Studio_V	V6020
SonarQube	Include Page SonarQube_V SonarQube_V	S3518	Zero should not be a possible denominator

Related Guidelines

...

...

...

Bibliography

...

...

...

...

...

Operators"
[Seacord 05]	Chapter 5, "Integers"
[Seacord 2015]	Image Added NUM02-J. Ensure that division and modulo operations do not result in divide-by-zero errors LiveLesson
[Warren 02]	Chapter 2, "Basics"

...

Image Added Image Added Image Added \[[MITRE 07|AA. Bibliography#MITRE 07]\] [CWE ID 369|http://cwe.mitre.org/data/definitions/369.html], "Divide By Zero" \[[Seacord 05|AA. Bibliography#Seacord 05]\] Chapter 5, "Integers" \[[Warren 02|AA. Bibliography#Warren 02]\] Chapter 2, "Basics"EXP10-J. Ensure that autoboxed values have the intended type      02. Expressions (EXP)      EXP12-J. Use the same type for the second and third operands in conditional expressions