Attacker Value
Very High
(2 users assessed)
Exploitability
High
(2 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
4

CVE-2020-1337

Disclosure Date: August 17, 2020
Add any MITRE ATT&CK Tactics to the list below that apply to this CVE.

Description

An elevation of privilege vulnerability exists when the Windows Print Spooler service improperly allows arbitrary writing to the file system, aka ‘Windows Print Spooler Elevation of Privilege Vulnerability’.

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6
Ratings
Technical Analysis

CVE-2020-1337 is a bypass of (PrintDemon) CVE-2020-1048’s patch via a Junction Directory, made to remediate an Elevation of Privileges (EoP)\Local Privilege Escalation (LPE) vulnerability affecting the Windows’ Print Spooler Service. The vulnerability does require low privilege access and for the spooler service to restart.
The patch appeared in Microsoft’s patch Tuesday (11th August 2020) – https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2020-1337#ID0EWIAC.

Vulnerability description, root cause analysis and PoC code on https://voidsec.com/cve-2020-1337-printdemon-is-dead-long-live-printdemon/

4
Ratings
Technical Analysis

This is a print spooler vulnerability similar to CVE-2020-1048, but it uses a specially-crafted *.SHD to trigger a print to a trusted location. Introduced at Blackhat on August 6, 2020, a patch is expected to appear next week in Microsoft’s patch Tuesday.
The vulnerability does require low privilege access and for the spooler service to restart.
PoC will be uploaded to https://github.com/SafeBreach-Labs/spooler on August 12.
This is extremely valuable to attackers. The exploit is most likely present on all versions of Windows from Windows 7 to present and the race is now on to patch it while PoCs are already in the wild.

General Information

Vendors

  • Microsoft

Products

  • Windows 10 Version 2004 for 32-bit Systems
  • Windows 10 Version 2004 for ARM64-based Systems
  • Windows 10 Version 2004 for x64-based Systems
  • Windows Server, version 2004 (Server Core installation)
  • Windows 10 Version 1803 for 32-bit Systems
  • Windows 10 Version 1803 for x64-based Systems
  • Windows 10 Version 1803 for ARM64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 1809 for ARM64-based Systems
  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows 10 Version 1909 for 32-bit Systems
  • Windows 10 Version 1909 for x64-based Systems
  • Windows 10 Version 1909 for ARM64-based Systems
  • Windows Server, version 1909 (Server Core installation)
  • Windows 10 Version 1709 for 32-bit Systems
  • Windows 10 Version 1709 for x64-based Systems
  • Windows 10 Version 1709 for ARM64-based Systems
  • Windows 10 Version 1903 for 32-bit Systems
  • Windows 10 Version 1903 for x64-based Systems
  • Windows 10 Version 1903 for ARM64-based Systems
  • Windows Server, version 1903 (Server Core installation)
  • Windows 10 for 32-bit Systems
  • Windows 10 for x64-based Systems
  • Windows 10 Version 1607 for 32-bit Systems
  • Windows 10 Version 1607 for x64-based Systems
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)
  • Windows 7 for 32-bit Systems Service Pack 1
  • Windows 7 for x64-based Systems Service Pack 1
  • Windows 8.1 for 32-bit systems
  • Windows 8.1 for x64-based systems
  • Windows RT 8.1
  • Windows Server 2008 for 32-bit Systems Service Pack 2
  • Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for x64-based Systems Service Pack 2
  • Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
  • Windows Server 2012
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)

Additional Info

Technical Analysis