CWE-1252: CPU Hardware Not Configured to Support Exclusivity of Write and Execute Operations
The CPU is not configured to provide hardware support for exclusivity of write and execute operations on memory. This allows an attacker to execute data from all of memory.
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Overview
CPUs provide a special bit that supports exclusivity of write and execute operations. This bit is used to segregate areas of memory to either mark them as code (instructions, which can be executed) or data (which should not be executed). In this way, if a user can write to a region of memory, the user cannot execute from that region and vice versa. This exclusivity provided by special hardware bit is leveraged by the operating system to protect executable space. While this bit is available in most modern processors by default, in some CPUs the exclusivity is implemented via a memory-protection unit (MPU) and memory-management unit (MMU) in which memory regions can be carved out with exact read, write, and execute permissions. However, if the CPU does not have an MMU/MPU, then there is no write exclusivity.
Common consequences
What can happen when CWE-1252 is exploited.
Execute Unauthorized Code or Commands
Affects: Confidentiality, Integrity
Without configuring exclusivity of operations via segregated areas of memory, an attacker may be able to inject malicious code onto memory and later execute it.
How it happens
When it is introduced
Typically introduced during these phases of the software lifecycle.
Applies to
Technologies