netskope CVE Vulnerabilities & Metrics

Netskope was notified about a security gap in Netskope Client enrollment process where NSClient is using a static token “Orgkey” as authentication parameter. Since this is a static token, if leaked, cannot be rotated or revoked. A malicious actor can use this token to enroll NSClient from a customer’s tenant and impersonate a user.

Netskope was made aware of a security vulnerability in its NSClient product for version 100 & prior where a malicious non-admin user can disable the Netskope client by using a specially-crafted package. The root cause of the problem was a user control code when called by a Windows ServiceController did not validate the permissions associated with the user before executing the user control code. This user control code had permissions to terminate the NSClient service. 

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.

The Netskope client service running with NT\SYSTEM privileges accepts network connections from localhost to start various services and execute commands. The connection handling function of Netskope client before R100 in this service utilized a relative path to download and unzip configuration files on the machine. This relative path provided a way for local users to write arbitrary files at a location which is accessible to only higher privileged users. This can be exploited by local users to execute code with NT\SYSTEM privileges on the end machine.

Netskope client is impacted by a vulnerability where an authenticated, local attacker can view sensitive information stored in NSClient logs which should be restricted. The vulnerability exists because the sensitive information is not masked/scrubbed before writing in the logs. A malicious user can use the sensitive information to download data and impersonate another user.

Netskope client prior to 89.x on macOS is impacted by a local privilege escalation vulnerability. The XPC implementation of nsAuxiliarySvc process does not perform validation on new connections before accepting the connection. Thus any low privileged user can connect and call external methods defined in XPC service as root, elevating their privilege to the highest level.

Netskope Client through 77 allows low-privileged users to elevate their privileges to NT AUTHORITY\SYSTEM.

A CSV injection vulnerability in the Admin portal for Netskope 75.0 allows an unauthenticated user to inject malicious payload in admin's portal thus leads to compromise admin's system.

The Netskope client service, v57 before 57.2.0.219 and v60 before 60.2.0.214, running with NT\SYSTEM privilege, accepts network connections from localhost. The connection handling function in this service suffers from command injection vulnerability. Local users can use this vulnerability to execute code with NT\SYSTEM privilege.

The Netskope client service, v57 before 57.2.0.219 and v60 before 60.2.0.214, running with NT\SYSTEM privilege, accepts network connections from localhost. The connection handling function in this service suffers from a stack based buffer overflow in "doHandshakefromServer" function. Local users can use this vulnerability to trigger a crash of the service and potentially cause additional impact on the system.