CWE-1335
Incorrect Bitwise Shift of Integer
Draft
2021-07-20
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2025-12-11
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Name: Incorrect Bitwise Shift of Integer
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.
CWE Description
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.
General Informations
Modes Of Introduction
Implementation : Adding shifts without properly verifying the size and sign of the shift amount.Applicable Platforms
Language
Name: C (Undetermined)Name: C++ (Undetermined)
Name: C# (Undetermined)
Name: Java (Undetermined)
Name: JavaScript (Undetermined)
Operating Systems
Class: Not OS-Specific (Undetermined)Technologies
Class: Not Technology-Specific (Undetermined)Common Consequences
| Scope | Impact | Likelihood |
|---|---|---|
| Integrity | DoS: Crash, Exit, or Restart |
Observed Examples
| References | Description |
|---|---|
CVE-2009-4307 | An unexpected large value in the ext4 filesystem causes an overshift condition resulting in a divide by zero. |
CVE-2012-2100 | An unexpected large value in the ext4 filesystem causes an overshift condition resulting in a divide by zero - fix of CVE-2009-4307. |
CVE-2020-8835 | An overshift in a kernel allowed out of bounds reads and writes resulting in a root takeover. |
CVE-2015-1607 | Program is not properly handling signed bitwise left-shifts causing an overlapping memcpy memory range error. |
CVE-2016-9842 | Compression function improperly executes a signed left shift of a negative integer. |
CVE-2018-18445 | Some kernels improperly handle right shifts of 32 bit numbers in a 64 bit register. |
CVE-2013-4206 | Putty has an incorrectly sized shift value resulting in an overshift. |
CVE-2018-20788 | LED driver overshifts under certain conditions resulting in a DoS. |
Potential Mitigations
Phases : ImplementationImplicitly or explicitly add checks and mitigation for negative or over-shift values.
Detection Methods
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.)Effectiveness : High
Vulnerability Mapping Notes
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.Comment : 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.
Submission
| Name | Organization | Date | Date release | Version |
|---|---|---|---|---|
| CWE Content Team | MITRE | 4.5 |
Modifications
| Name | Organization | Date | Comment |
|---|---|---|---|
| CWE Content Team | MITRE | updated Demonstrative_Examples, Observed_Examples | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Mapping_Notes | |
| CWE Content Team | MITRE | updated Detection_Factors, Weakness_Ordinalities |
