CVE-2025-43715: CWE-754 Improper Check for Unusual or Exceptional Conditions in Nullsoft Nullsoft Scriptable Install System
Description
CVE-2025-43715 is a local privilege escalation vulnerability in Nullsoft Scriptable Install System (NSIS) on Windows versions before 3.11. It arises from improper handling of the temporary plugins directory creation under %WINDIR%\temp, allowing unprivileged users to exploit a race condition and escalate privileges to SYSTEM during installation.
CVSS v3.1
Score 8.1high
Affected software
Nullsoft
Nullsoft Scriptable Install System
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Nullsoft Scriptable Install System (NSIS) versions prior to 3.11 on Windows contain a vulnerability where the temporary plugins directory is created under %WINDIR%\temp without proper restrictions. The EW_CREATEDIR function does not consistently set the CreateRestrictedDirectory error flag, enabling local users to place a crafted executable by winning a race condition. This flaw allows escalation of privileges to SYSTEM during installation.
Potential Impact
An attacker with local access can exploit this race condition to execute arbitrary code with SYSTEM privileges, leading to full system compromise. The vulnerability has a high severity with a CVSS score of 8.1, indicating significant confidentiality, integrity, and availability impacts.
Mitigation Recommendations
A fix is available in Nullsoft Scriptable Install System version 3.11. Users should upgrade to version 3.11 or later to remediate this vulnerability. No additional mitigation guidance is provided in the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2025-04-17T00:00:00.000Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad02dbd2cdf04f656f2a272
Added to database: 10/15/2026, 01:34:53 UTC
Last enriched: 10/15/2026, 01:48:16 UTC
Last updated: 10/15/2026, 01:49:44 UTC
Views: 5
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