CWE-135 Details

CWE-135

Incorrect Calculation of Multi-Byte String Length
Draft
2006-07-19
00h00 +00:00
2025-12-11
00h00 +00:00
CWE Mitre.org
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Name: Incorrect Calculation of Multi-Byte String Length

The product does not correctly calculate the length of strings that can contain wide or multi-byte characters.

Allgemeine Informationen

Einführungsmodi

Implementation

Anwendbare Plattformen

Sprache

Name: C (Undetermined)
Name: C++ (Undetermined)

Häufige Konsequenzen

Bereich Auswirkung Wahrscheinlichkeit
Integrity
Confidentiality
Availability		Execute Unauthorized Code or Commands

Note: This weakness may lead to a buffer overflow. Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. This can often be used to subvert any other security service.
Availability
Confidentiality		Read Memory, DoS: Crash, Exit, or Restart, DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory)

Note: Out of bounds memory access will very likely result in the corruption of relevant memory, and perhaps instructions, possibly leading to a crash. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
ConfidentialityRead Memory

Note: In the case of an out-of-bounds read, the attacker may have access to sensitive information. If the sensitive information contains system details, such as the current buffer's position in memory, this knowledge can be used to craft further attacks, possibly with more severe consequences.

Mögliche Gegenmaßnahmen

Phases : Implementation
Always verify the length of the string unit character.
Phases : Implementation
Use length computing functions (e.g. strlen, wcslen, etc.) appropriately with their equivalent type (e.g.: byte, wchar_t, etc.)

Erkennungsmethoden

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.)
Wirksamkeit : High

Hinweise zur Schwachstellen-Zuordnung

Begründung : 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.
Kommentar : 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.

Referenzen

REF-7

Writing Secure Code
Michael Howard, David LeBlanc.
https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223

REF-18

The CLASP Application Security Process
Secure Software, Inc..
https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf

Einreichung

Name Organisation Datum Veröffentlichungsdatum Version
CLASP 2006-07-19 +00:00 2006-07-19 +00:00 Draft 3

Änderungen

Name Organisation Datum Kommentar
Eric Dalci Cigital 2008-07-01 +00:00 updated Potential_Mitigations, Time_of_Introduction
CWE Content Team MITRE 2008-09-08 +00:00 updated Applicable_Platforms, Relationships, Other_Notes, Taxonomy_Mappings
CWE Content Team MITRE 2008-11-24 +00:00 updated Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2009-05-27 +00:00 updated Description
CWE Content Team MITRE 2010-02-16 +00:00 updated Demonstrative_Examples, References
CWE Content Team MITRE 2011-06-01 +00:00 updated Common_Consequences, Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2011-06-27 +00:00 updated Common_Consequences
CWE Content Team MITRE 2012-05-11 +00:00 updated Common_Consequences, Demonstrative_Examples, Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2012-10-30 +00:00 updated Potential_Mitigations
CWE Content Team MITRE 2014-06-23 +00:00 updated Enabling_Factors_for_Exploitation, Other_Notes
CWE Content Team MITRE 2014-07-30 +00:00 updated Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2017-11-08 +00:00 updated Enabling_Factors_for_Exploitation, Modes_of_Introduction, References, Taxonomy_Mappings
CWE Content Team MITRE 2018-03-27 +00:00 updated References
CWE Content Team MITRE 2019-01-03 +00:00 updated Taxonomy_Mappings
CWE Content Team MITRE 2021-03-15 +00:00 updated References
CWE Content Team MITRE 2023-01-31 +00:00 updated Description
CWE Content Team MITRE 2023-04-27 +00:00 updated Detection_Factors, Relationships
CWE Content Team MITRE 2023-06-29 +00:00 updated Mapping_Notes
CWE Content Team MITRE 2024-07-16 +00:00 updated Common_Consequences
CWE Content Team MITRE 2025-12-11 +00:00 updated Weakness_Ordinalities
Die auf CVE Find präsentierten Informationen stammen aus mehreren sorgfältig ausgewählten Referenzquellen. CVE-Daten werden von der MITRE Corporation und der National Vulnerability Database (NVD) bereitgestellt. Der Katalog bekannter ausgenutzter Schwachstellen (KEV) stammt von der Cybersecurity and Infrastructure Security Agency (CISA), während EPSS-Scores von FIRST.org kommen. Darüber hinaus werden Daten zu Software-Schwachstellen (CWE) und häufigen Angriffsmustern (CAPEC) von der MITRE Corporation gepflegt, und Informationen zu Hardware- und Software-Konfigurationen (CPE) werden von der NVD bereitgestellt.