Name: Vietnam CyStack Joint Stock Company
Address: Tan Hong Ha Complex, 317 Truong Chinh Street, Hanoi, Vietnam, 100000, VN
Telephone: (+84) 247 109 9656
Price range: Negotiable

Official definition

ByMitre CWE

The product checks a value to ensure that it is less than or equal to a maximum, but it does not also verify that the value is greater than or equal to the minimum.

Characteristics

Alternate terms

Signed comparison — The "signed comparison" term is often used to describe when the product uses a signed variable and checks it to ensure that it is less than a maximum value (typically a maximum buffer size), but does not verify that it is greater than 0.

Modes of introduction

Implementation: Some products use signed integers or floats even when their values are only expected to be positive or 0. An input validation check might assume that the value is positive, and only check for the maximum value.

Common consequences

Impact	Scope	Explanation
Modify Memory, Read Memory	Confidentiality, Integrity	If a negative value is used to access memory, buffers, or other indexable structures, it could access memory outside the bounds of the buffer.
DoS: Resource Consumption (Memory), DoS: Resource Consumption (Other)	Availability	In some contexts, a negative value could lead to resource consumption, e.g., if the negative value is used for memory allocation.
Modify Application Data, Execute Unauthorized Code or Commands	Integrity, Confidentiality, Availability	An attacker could modify the structure of the message or data being sent to the downstream component, possibly injecting commands.
Varies by Context, Unexpected State	Integrity	The use of a negative number in a positive-only context could have security implications for other types of resources. For example, a shopping cart might check that the user is not requesting more than 10 items, but a request for -3 items could cause the application to calculate a negative price and credit the attacker's account.

Risk mitigations

Enforcement by Conversion · ImplementationIf the number to be used is always expected to be positive, change the variable type from signed to unsigned or size_t.
Input Validation · ImplementationIf the number to be used could have a negative value based on the specification (thus requiring a signed value), but the number should only be positive to preserve code correctness, then include a check to ensure that the value is positive.

Detection methods

Method	Approach	Effectiveness
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.)	-

Representative vulnerabilities

Below are representative vulnerabilities related to this CWE, prioritized by severity.

Sources (2)

MITRE CWE

CWE Terms of Use

CWE-839: Numeric Range Comparison Without Minimum Check

What is CWE-839?

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Vulnerabilities mapped to CWE-839

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Official definition

Characteristics

Alternate terms

Modes of introduction

Common consequences

Risk mitigations

Detection methods

Representative vulnerabilities

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