vendor:
NoMachine
by:
Daniele Linguaglossa
8,8
CVSS
HIGH
Local Privilege Escalation
264
CWE
Product Name: NoMachine
Affected Version From: 5.3.9
Affected Version To: 5.3.9
Patch Exists: Yes
Related CWE: CVE-2017-12763
CPE: a:nomachine:nomachine
Metasploit:
N/A
Other Scripts:
N/A
Tags: N/A
CVSS Metrics: N/A
Nuclei References:
N/A
Nuclei Metadata: N/A
Platforms Tested: OSX
2017
NoMachine LPE – Local Privilege Escalation
NoMachine uses a file called nxexec in order to execute different action as super user, nxexec allow to execute sh files within a sandboxed path, additionally other checks such as parent process name, parent process path are performed in order to be sure only NoMachine application are allowed to execute nxexec. nxnode.bin allow to spoof a local path via NX_SYSTEM environment variable, this is use to craft a path where a perl file will be executed, this PoC exploit the NX_SYSTEM variable in order to allow a custom perl file to call nxexec and execute privileged nxcat.sh script in order to read any file on filesystem.
Mitigation:
Ensure that the NX_SYSTEM environment variable is not set to a user-controlled value.