Détail du CWE-1335

An integer value is specified to be shifted by a negative amount or an amount greater than or equal to the number of bits contained in the value causing an unexpected or indeterminate result.

Specifying a value to be shifted by a negative amount is undefined in various languages. Various computer architectures implement this action in different ways. The compilers and interpreters when generating code to accomplish a shift generally do not do a check for this issue.

Specifying an over-shift, a shift greater than or equal to the number of bits contained in a value to be shifted, produces a result which varies by architecture and compiler. In some languages, this action is specifically listed as producing an undefined result.

Modes d'introduction

Implementation : Adding shifts without properly verifying the size and sign of the shift amount.

Plateformes applicables

Langue

Name: C (Undetermined)
Name: C++ (Undetermined)
Name: C# (Undetermined)
Name: Java (Undetermined)
Name: JavaScript (Undetermined)

Systèmes d’exploitation

Class: Not OS-Specific (Undetermined)

Technologies

Class: Not Technology-Specific (Undetermined)

Conséquences courantes

Exemples observés

Mesures d’atténuation potentielles

Phases : Implementation
Implicitly or explicitly add checks and mitigation for negative or over-shift values.

Méthodes de détection

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.)
Efficacité : High

Notes de cartographie des vulnérabilités

Justification : This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Commentaire : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Soumission

Modifications