CVE-2022-4149

Local privilege escalation using log file

Published Jun 15, 2023 CVSS 3.1 · 7 High EPSS < 1% KEV · Not listed
Description
The Netskope client service (prior to R96) on Windows runs as NT AUTHORITY\SYSTEM which writes log files to a writable directory (C:\Users\Public\netSkope) for a standard user. The files are created and written with a SYSTEM account except one file (logplaceholder) which inherits permission giving all users full access control list. Netskope client restricts access to this file by allowing only read permissions as a standard user. Whenever the Netskope client service restarts, it deletes the logplaceholder and recreates, creating a race condition, which can be exploited by a malicious local user to create the file and set ACL permissions on the file. Once the file is created by a malicious user with proper ACL permissions, all files within C:\Users\Public\netSkope\ becomes modifiable by the unprivileged user. By using Windows pseudo-symlink, these files can be pointed to other places in the system and thus malicious users will be able to elevate privileges.

Remediation

Vendor Solution

Netskope has patched the vulnerability and released a binary with a fix. Customers are recommended to upgrade their Netskope clients to v100 or later. Netskope download Instructions – Download Netskope Client and Scripts – Netskope Support https://support.netskope.com/s/article/Download-Netskope-Client-and-Scripts


Vendor Workaround

Netskope recommends using hardening guidelines listed here - – https://docs.netskope.com/en/netskope-client-hardening.html https://docs.netskope.com/en/netskope-client-hardening.html  

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
EUVD EUVD EUVD-2022-51510 The Netskope client service (prior to R96) on Windows runs as NT AUTHORITY\SYSTEM which writes log files to a writable directory (C:\Users\Public\netSkope) for a standard user. The files are created and written with a SYSTEM account except one file (logplaceholder) which inherits permission giving all users full access control list. Netskope client restricts access to this file by allowing only read permissions as a standard user. Whenever the Netskope client service restarts, it deletes the logplaceholder and recreates, creating a race condition, which can be exploited by a malicious local user to create the file and set ACL permissions on the file. Once the file is created by a malicious user with proper ACL permissions, all files within C:\Users\Public\netSkope\ becomes modifiable by the unprivileged user. By using Windows pseudo-symlink, these files can be pointed to other places in the system and thus malicious users will be able to elevate privileges.
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Netskope
Published
Updated
Dec 12, 2024, 5:05 PM
Reserved
Nov 28, 2022, 12:19 PM
Status
Modified
Published
Jun 15, 2023, 7:15 AM
Modified
Jun 17, 2026, 5:20 AM