Privilege Escalation Vulnerability in Nullsoft Scriptable Install System by Nullsoft

CVE-2025-43715

What is CVE-2025-43715?

A vulnerability in the Nullsoft Scriptable Install System (NSIS) allows local users on Windows to escalate their privileges to SYSTEM during installation processes. This occurs due to a race condition in the management of the temporary plugins directory, which is improperly created under %WINDIR%\temp. Unprivileged users may exploit this by adding a malicious executable. The underlying issue arises as the EW_CREATEDIR command does not consistently trigger the CreateRestrictedDirectory error flag, leading to potential unauthorized access.

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