CVE-2025-68623
Published: 11 March 2026
Summary
CVE-2025-68623 is a high-severity Improper Access Control (CWE-284) vulnerability in Microsoft DirectX End-User (inferred from references). Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Executable Installer File Permissions Weakness (T1574.005); ranked at the 2.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 CM-14 (Signed Components) and SI-7 (Software, Firmware, and Information Integrity).
Deeper analysis
CVE-2025-68623 affects the Microsoft DirectX End-User Runtime Web Installer version 9.29.1974.0, where a low-privilege user can replace an executable file during the installation process, potentially leading to unintended elevation of privileges. The installer operates with HIGH integrity and downloads executables and DLLs into the %TEMP% folder, which is writable by standard users. It then executes the downloaded executable with HIGH integrity to finalize the installation, but lacks protections against file replacement in this location.
A low-privilege local attacker (PR:L) can exploit this by replacing the downloaded executable in %TEMP% with a malicious one under their control before the installer executes it. This allows the attacker's code to run with HIGH integrity privileges. From there, the code can further escalate to SYSTEM level by registering and executing a service, enabling a full privilege escalation chain from a standard user to SYSTEM. The vulnerability has a CVSS v3.1 base score of 8.8 (AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H) and is associated with CWE-284 (Improper Access Control).
Advisories from Talos Intelligence (TALOS-2025-2293) detail the issue, while the Microsoft download page for the installer is available at https://www.microsoft.com/en-us/download/details.aspx?id=35. Microsoft, as the supplier, disputes the vulnerability record, stating it reflects behavior as designed, with no patches or mitigations explicitly mentioned in the provided details.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-208593
Vulnerability details
In Microsoft DirectX End-User Runtime Web Installer 9.29.1974.0, a low-privilege user can replace an executable file during the installation process, which may result in unintended elevation of privileges. During installation, the installer runs with HIGH integrity and downloads executables and…
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DLLs to the %TEMP% folder - writable by standard users. Subsequently, the installer executes the downloaded executable with HIGH integrity to complete the application installation. However, an attacker can replace the downloaded executable with a malicious, user-controlled executable. When the installer executes this replaced file, it runs the attacker's code with HIGH integrity. Since code running at HIGH integrity can escalate to SYSTEM level by registering and executing a service, this creates a complete privilege escalation chain from standard user to SYSTEM. NOTE: The Supplier disputes this record stating that they have determined this to be the behavior as designed.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Installer executable in user-writable %TEMP% directly matches Executable Installer File Permissions Weakness; resulting high-integrity context enables creation of a Windows service for SYSTEM escalation.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Requiring verification of digital signatures for downloaded executables before high-integrity execution directly prevents the installer from running attacker-replaced malicious files from the user-writable %TEMP% folder.
Performing integrity checks (e.g., cryptographic hashes or signatures) on downloaded installer components before execution prevents or detects tampering in the writable %TEMP% directory.
Verifying the authenticity of downloaded system components prior to elevated-privilege execution ensures attacker-replaced executables in %TEMP% cannot be used in the privilege escalation chain.