CWE-562: Return of Stack Variable Address

Description

A function returns the address of a stack variable, which will cause unintended program behavior, typically in the form of a crash.

Because local variables are allocated on the stack, when a program returns a pointer to a local variable, it is returning a stack address. A subsequent function call is likely to re-use this same stack address, thereby overwriting the value of the pointer, which no longer corresponds to the same variable since a function's stack frame is invalidated when it returns. At best this will cause the value of the pointer to change unexpectedly. In many cases it causes the program to crash the next time the pointer is dereferenced.

Potential Impact

Demonstrative Examples

char* getName() {char name[STR_MAX];fillInName(name);return name;}

Mitigations & Prevention

Detection Methods

• Fuzzing High — Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption,
• Automated Static Analysis High — 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 sea
• Automated Dynamic Analysis Moderate — Use tools that are integrated during compilation to insert runtime error-checking mechanisms related to memory safety errors, such as AddressSanitizer (ASan) for C/C++ [REF-1518].

Real-World CVE Examples

Related Weaknesses

Taxonomy Mappings

• CERT C Secure Coding: DCL30-C — Declare objects with appropriate storage durations
• CERT C Secure Coding: POS34-C — Do not call putenv() with a pointer to an automatic variable as the argument
• Software Fault Patterns: SFP1 — Glitch in computation