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CWE-843

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CWE-843

Access of Resource Using Incompatible Type ('Type Confusion')

Base
Incomplete

Description

The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

{"xhtml:p":["When the product accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties. In languages without memory safety, such as C and C++, type confusion can lead to out-of-bounds memory access.","While this weakness is frequently associated with unions when parsing data with many different embedded object types in C, it can be present in any application that can interpret the same variable or memory location in multiple ways.","This weakness is not unique to C and C++. For example, errors in PHP applications can be triggered by providing array parameters when scalars are expected, or vice versa. Languages such as Perl, which perform automatic conversion of a variable of one type when it is accessed as if it were another type, can also contain these issues."]}

Related Weaknesses

Common Consequences

Scope

Availability
Integrity
Confidentiality

Impact

Read Memory, Modify Memory, Execute Unauthorized Code or Commands, DoS: Crash, Exit, or Restart

CVE-2025-32352

Type confusion in PHP app allows authentication bypass when users have passwords whose MD5 hashes can be interpreted as numbers

CVE-2010-4577

Type confusion in CSS sequence leads to out-of-bounds read.

CVE-2011-0611

Size inconsistency allows code execution, first discovered when it was actively exploited in-the-wild.

CVE-2010-0258

Improperly-parsed file containing records of different types leads to code execution when a memory location is interpreted as a different object than intended.

Applicable Platforms

C
C++

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