CWE-123 - Write-what-where Condition

Description: Any condition where the attacker has the ability to write an arbitrary value to an arbitrary location, often as the result of a buffer overflow.

Common Consequences: Scope: Integrity, Confidentiality, Availability, Access Control
Impact: Modify Memory, Execute Unauthorized Code or Commands, Gain Privileges or Assume Identity, DoS: Crash, Exit, or Restart, Bypass Protection Mechanism
Notes: Clearly, write-what-where conditions can be used to write data to areas of memory outside the scope of a policy. Also, they almost invariably can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. If the attacker can overwrite a pointer's worth of memory (usually 32 or 64 bits), they can redirect a function pointer to their own malicious code. Even when the attacker can only modify a single byte arbitrary code execution can be possible. Sometimes this is because the same problem can be exploited repeatedly to the same effect. Other times it is because the attacker can overwrite security-critical application-specific data -- such as a flag indicating whether the user is an administrator.
Scope: Integrity, Availability
Impact: DoS: Crash, Exit, or Restart, Modify Memory
Notes: Many memory accesses can lead to program termination, such as when writing to addresses that are invalid for the current process.
Scope: Access Control, Other
Impact: Bypass Protection Mechanism, Other
Notes: When the consequence is arbitrary code execution, this can often be used to subvert any other security service.