Moderate
CVE-2022-21999
CVE-2022-21999
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Technical Analysis
This is a useful vulnerability; however, an existing session on the target is required, and escalation of privileges can sometimes depend on luck. To achieve the directory creation and ultimately the file write, one first needs to reinitialize the print spooler. There exists one primitive to do this using SetPrinterDataEx() and AppVTerminator.dll as a Point and Print dll, but it’s limited to two uses because the print spooler will not automatically restart after two crashes. If the print spooler has reached its maximum number of restarts, then this exploit will only work by restarting the system completely, which is not particularly stealthy. Additionally, the previously-mentioned primitive is limited, as Windows 7 does not appear to have the AppVTerminator dll.
Assuming that the attacker has a printer handle with the PRINTER_ACCESS_ADMINISTER privilege and the ability to restart the print spooler, this vulnerability is fairly easy to exploit. Create a temp directory, set the SpoolDirectory to the temp path with the version 4 directory appended (in UNC path form), create junction between the temp path and the printer driver directory, restart spooler, write malicious dll, then load the dll.
I wouldn’t call this the first priority in the list of vulnerabilities to patch mainly due to an existing session being a requirement and success potentially depending on a reboot, but it should certainly be patched.
CVSS V3 Severity and Metrics
General Information
Vendors
- microsoft
Products
- windows 10 1507,
- windows 10 1607,
- windows 10 1809,
- windows 10 1909,
- windows 10 20h2,
- windows 10 21h1,
- windows 10 21h2,
- windows 11 21h2,
- windows 7 -,
- windows 8.1 -,
- windows rt 8.1 -,
- windows server 2008 -,
- windows server 2008 r2,
- windows server 2012 -,
- windows server 2012 r2,
- windows server 2016,
- windows server 2019,
- windows server 2022,
- windows server 20h2
Metasploit Modules
References
Exploit
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