CWE - CWE-676: Use of Potentially Dangerous Function (4.20)
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    CWE-676: Use of Potentially Dangerous Function

    Weakness ID: 676
    Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
    Abstraction: Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.
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    + Description
    The product invokes a potentially dangerous function that could introduce a vulnerability if it is used incorrectly, but the function can also be used safely.
    + Common Consequences
    Section HelpThis table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
    Impact Details

    Varies by Context; Quality Degradation; Unexpected State

    		Scope: Other

    If the function is used incorrectly, then it could result in security problems.
    + Potential Mitigations
    Phase(s) Mitigation

    Build and Compilation; Implementation
    Identify a list of prohibited API functions and prohibit developers from using these functions, providing safer alternatives. In some cases, automatic code analysis tools or the compiler can be instructed to spot use of prohibited functions, such as the "banned.h" include file from Microsoft's SDL. [REF-554] [REF-1009] [REF-7]
    + Relationships
    Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
    + Relevant to the view "Research Concepts" (View-1000)
    Nature Type ID Name
    ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 1177 Use of Prohibited Code
    ParentOf Variant Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource. 785 Use of Path Manipulation Function without Maximum-sized Buffer
    + Relevant to the view "Software Development" (View-699)
    Nature Type ID Name
    MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1228 API / Function Errors
    + Modes Of Introduction
    Section HelpThe different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.
    Phase Note
    Implementation
    + Applicable Platforms
    Section HelpThis listing shows possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.
    Languages

    C (Undetermined Prevalence)

    C++ (Undetermined Prevalence)

    + Likelihood Of Exploit
    High
    + Demonstrative Examples

    Example 1


    The following code attempts to create a local copy of a buffer to perform some manipulations to the data.

    (bad code)
    Example Language: C 
    void manipulate_string(char * string){
    char buf[24];
    strcpy(buf, string);
    ...
    }

    However, the programmer does not ensure that the size of the data pointed to by string will fit in the local buffer and copies the data with the potentially dangerous strcpy() function. This may result in a buffer overflow condition if an attacker can influence the contents of the string parameter.



    + Selected Observed Examples

    Note: this is a curated list of examples for users to understand the variety of ways in which this weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.

    Reference Description
    Library has multiple buffer overflows using sprintf() and strcpy()
    Buffer overflow using strcat()
    Buffer overflow using strcpy()
    Buffer overflow using strcpy()
    Vulnerable use of strcpy() changed to use safer strlcpy()
    Buffer overflow using strcpy()
    + Weakness Ordinalities
    Ordinality Description
    Primary
    (where the weakness exists independent of other weaknesses)
    Indirect
    (where the weakness is a quality issue that might indirectly make it easier to introduce security-relevant weaknesses or make them more difficult to detect)
    + Detection Methods
    Method Details

    Automated Static Analysis - Binary or Bytecode

    According to SOAR [REF-1479], the following detection techniques may be useful:

    Highly cost effective:
    • Bytecode Weakness Analysis - including disassembler + source code weakness analysis
    • Binary Weakness Analysis - including disassembler + source code weakness analysis
    Cost effective for partial coverage:
    • Binary / Bytecode Quality Analysis
    • Binary / Bytecode simple extractor - strings, ELF readers, etc.

    Effectiveness: High

    Manual Static Analysis - Binary or Bytecode

    According to SOAR [REF-1479], the following detection techniques may be useful:

    Cost effective for partial coverage:
    • Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

    Effectiveness: SOAR Partial

    Dynamic Analysis with Manual Results Interpretation

    According to SOAR [REF-1479], the following detection techniques may be useful:

    Highly cost effective:
    • Debugger
    Cost effective for partial coverage:
    • Monitored Virtual Environment - run potentially malicious code in sandbox / wrapper / virtual machine, see if it does anything suspicious

    Effectiveness: High

    Manual Static Analysis - Source Code

    According to SOAR [REF-1479], the following detection techniques may be useful:

    Highly cost effective:
    • Manual Source Code Review (not inspections)
    Cost effective for partial coverage:
    • Focused Manual Spotcheck - Focused manual analysis of source

    Effectiveness: High

    Automated Static Analysis - Source Code

    According to SOAR [REF-1479], the following detection techniques may be useful:

    Highly cost effective:
    • Source code Weakness Analyzer
    • Context-configured Source Code Weakness Analyzer
    Cost effective for partial coverage:
    • Warning Flags
    • Source Code Quality Analyzer

    Effectiveness: High

    Automated Static Analysis

    According to SOAR [REF-1479], the following detection techniques may be useful:

    Cost effective for partial coverage:
    • Origin Analysis

    Effectiveness: SOAR Partial

    Architecture or Design Review

    According to SOAR [REF-1479], the following detection techniques may be useful:

    Highly cost effective:
    • Formal Methods / Correct-By-Construction
    • Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

    Effectiveness: High
    + Memberships
    Section HelpThis MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
    Nature Type ID Name
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 738 CERT C Secure Coding Standard (2008) Chapter 5 - Integers (INT)
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 743 CERT C Secure Coding Standard (2008) Chapter 10 - Input Output (FIO)
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 746 CERT C Secure Coding Standard (2008) Chapter 13 - Error Handling (ERR)
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 865 2011 Top 25 - Risky Resource Management
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 872 CERT C++ Secure Coding Section 04 - Integers (INT)
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 877 CERT C++ Secure Coding Section 09 - Input Output (FIO)
    MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 884 CWE Cross-section
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1001 SFP Secondary Cluster: Use of an Improper API
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1161 SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1165 SEI CERT C Coding Standard - Guidelines 10. Environment (ENV)
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1167 SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR)
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1169 SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON)
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1170 SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC)
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1412 Comprehensive Categorization: Poor Coding Practices
    MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1441 OWASP Top Ten 2025 Category A06:2025 - Insecure Design
    + Vulnerability Mapping Notes
    Usage ALLOWED
    (this CWE ID may be used to map to real-world vulnerabilities)
    Reason Acceptable-Use

    Rationale

    		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.

    Comments

    		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.
    + Notes

    Relationship

    This weakness is different than CWE-242 (Use of Inherently Dangerous Function). CWE-242 covers functions with such significant security problems that they can never be guaranteed to be safe. Some functions, if used properly, do not directly pose a security risk, but can introduce a weakness if not called correctly. These are regarded as potentially dangerous. A well-known example is the strcpy() function. When provided with a destination buffer that is larger than its source, strcpy() will not overflow. However, it is so often misused that some developers prohibit strcpy() entirely.
    + Taxonomy Mappings
    Mapped Taxonomy Name Node ID Fit Mapped Node Name
    7 Pernicious Kingdoms Dangerous Functions
    CERT C Secure Coding CON33-C CWE More Abstract Avoid race conditions when using library functions
    CERT C Secure Coding ENV33-C CWE More Abstract Do not call system()
    CERT C Secure Coding ERR07-C Prefer functions that support error checking over equivalent functions that don't
    CERT C Secure Coding ERR34-C CWE More Abstract Detect errors when converting a string to a number
    CERT C Secure Coding FIO01-C Be careful using functions that use file names for identification
    CERT C Secure Coding MSC30-C CWE More Abstract Do not use the rand() function for generating pseudorandom numbers
    CERT C Secure Coding STR31-C Imprecise Guarantee that storage for strings has sufficient space for character data and the null terminator
    Software Fault Patterns SFP3 Use of an improper API
    + References
    [REF-6] Katrina Tsipenyuk, Brian Chess and Gary McGraw. "Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors". NIST Workshop on Software Security Assurance Tools Techniques and Metrics. NIST. 2005-11-07.
    <https://samate.nist.gov/SSATTM_Content/papers/Seven%20Pernicious%20Kingdoms%20-%20Taxonomy%20of%20Sw%20Security%20Errors%20-%20Tsipenyuk%20-%20Chess%20-%20McGraw.pdf>.
    [REF-554] Michael Howard. "Security Development Lifecycle (SDL) Banned Function Calls". 2011-06.
    <https://learn.microsoft.com/en-us/previous-versions/bb288454(v=msdn.10)?redirectedfrom=MSDN>. (URL validated: 2026-04-24)
    [REF-1009] Tim Rains. "Microsoft's Free Security Tools - banned.h". 2012-08-30.
    <https://www.microsoft.com/en-us/security/blog/2012/08/30/microsofts-free-security-tools-banned-h/>. (URL validated: 2026-04-24)
    [REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 5, "Safe String Handling" Page 156, 160. 2nd Edition. Microsoft Press. 2002-12-04.
    <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.
    [REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 8, "C String Handling", Page 388. 1st Edition. Addison Wesley. 2006.
    [REF-1479] Gregory Larsen, E. Kenneth Hong Fong, David A. Wheeler and Rama S. Moorthy. "State-of-the-Art Resources (SOAR) for Software Vulnerability Detection, Test, and Evaluation". 2014-07.
    <https://www.ida.org/-/media/feature/publications/s/st/stateoftheart-resources-soar-for-software-vulnerability-detection-test-and-evaluation/p-5061.ashx>. (URL validated: 2025-09-05)
    + Content History
    + Submissions
    Submission Date Submitter Organization
    2008-04-11
    (CWE Draft 9, 2008-04-11)     		7 Pernicious Kingdoms
    + Modifications
    Modification Date Modifier Organization
    2026-04-30
    (CWE 4.20, 2026-04-30)     		CWE Content Team MITRE
    updated Potential_Mitigations, References
    2025-12-11
    (CWE 4.19, 2025-12-11)     		CWE Content Team MITRE
    updated Relationships
    2025-09-09
    (CWE 4.18, 2025-09-09)     		CWE Content Team MITRE
    updated Detection_Factors, References
    2023-06-29
    (CWE 4.12, 2023-06-29)     		CWE Content Team MITRE
    updated Mapping_Notes
    2023-04-27
    (CWE 4.11, 2023-04-27)     		CWE Content Team MITRE
    updated References, Relationships, Time_of_Introduction
    2023-01-31
    (CWE 4.10, 2023-01-31)     		CWE Content Team MITRE
    updated Description
    2021-03-15
    (CWE 4.4, 2021-03-15)     		CWE Content Team MITRE
    updated Demonstrative_Examples
    2020-12-10
    (CWE 4.3, 2020-12-10)     		CWE Content Team MITRE
    updated Demonstrative_Examples
    2020-02-24
    (CWE 4.0, 2020-02-24)     		CWE Content Team MITRE
    updated Detection_Factors, References, Relationships
    2019-01-03
    (CWE 3.2, 2019-01-03)     		CWE Content Team MITRE
    updated Relationships, Weakness_Ordinalities
    2018-03-27
    (CWE 3.1, 2018-03-27)     		CWE Content Team MITRE
    updated References
    2017-11-08
    (CWE 3.0, 2017-11-08)     		CWE Content Team MITRE
    updated Causal_Nature, References, Relationships, Taxonomy_Mappings
    2017-05-03
    (CWE 2.11, 2017-05-05)     		CWE Content Team MITRE
    updated Related_Attack_Patterns
    2014-07-30
    (CWE 2.8, 2014-07-31)     		CWE Content Team MITRE
    updated Detection_Factors, Relationships, Taxonomy_Mappings
    2012-05-11
    (CWE 2.2, 2012-05-15)     		CWE Content Team MITRE
    updated References, Related_Attack_Patterns, Relationships, Weakness_Ordinalities
    2011-09-13
    (CWE 2.1, 2011-09-13)     		CWE Content Team MITRE
    updated Potential_Mitigations, Relationships, Taxonomy_Mappings
    2011-06-27
    (CWE 2.0, 2011-06-27)     		CWE Content Team MITRE
    updated Common_Consequences, Observed_Examples, Potential_Mitigations, References, Relationships
    2011-06-01
    (CWE 1.13, 2011-06-01)     		CWE Content Team MITRE
    updated Common_Consequences
    2010-02-16
    (CWE 1.8, 2010-02-16)     		CWE Content Team MITRE
    updated Demonstrative_Examples, Other_Notes, References, Relationship_Notes
    2009-07-27
    (CWE 1.5, 2009-07-27)     		CWE Content Team MITRE
    updated Relationships
    2008-11-24
    (CWE 1.1, 2008-11-25)     		CWE Content Team MITRE
    updated Relationships, Taxonomy_Mappings
    2008-09-08
    (CWE 1.0, 2008-09-09)     		CWE Content Team MITRE
    updated Applicable_Platforms, Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities
    2008-07-01
    (CWE 1.0, 2008-09-09)     		Sean Eidemiller Cigital
    added/updated demonstrative examples
    2008-07-01
    (CWE 1.0, 2008-09-09)     		Eric Dalci Cigital
    updated Potential_Mitigations, Time_of_Introduction
    Page Last Updated: April 30, 2026