PROCESSVMWRITE

PROCESSVMWRITE (commonly seen as PROCESS_VM_WRITE or PROCESS_VM_WRITE access) is a Windows process access right used to permit writing to the memory of another process. It is defined in the Windows platform headers and typically specified when calling OpenProcess or similar functions to obtain a handle with targeted permissions. The constant value is commonly documented as 0x0020 and is used alongside other process access flags.

Practical use and requirements: PROCESSVMWRITE is required for API calls that modify a remote process’s address space, most notably WriteProcessMemory. In many scenarios WriteProcessMemory also requires PROCESS_VM_OPERATION (to change memory protections or perform operations) in addition to PROCESSVMWRITE. Higher privilege contexts or privileges such as SeDebugPrivilege may be necessary to open handles to processes owned by other users or the system.

Security and limitations: Granting PROCESSVMWRITE allows altering another process’s memory but does not confer code-execution rights by itself; additional steps (for example creating a remote thread) may be needed to execute injected code. Modern OS protections—Data Execution Prevention (DEP), Address Space Layout Randomization (ASLR), protected processes, and integrity level restrictions—can limit effective use of this access and are designed to mitigate malicious memory tampering. Best practices recommend requesting the minimal required access and respecting platform security guidance when interacting with other processes.