Advisory Details

December 11th, 2019

Microsoft Windows AppX Deployment Service Hard Link Escalation of Privilege Vulnerability

ZDI-19-1005
ZDI-CAN-9320

CVE ID CVE-2019-1483
CVSS SCORE 7.0, (AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H)
AFFECTED VENDORS Microsoft
AFFECTED PRODUCTS Windows
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on affected installations of Microsoft Windows. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the AppX Deployment Service. By creating a hard link, an attacker can abuse the service to overwrite the contents of a chosen file. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of SYSTEM.

ADDITIONAL DETAILS Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1483
DISCLOSURE TIMELINE
  • 2019-08-29 - Vulnerability reported to vendor
  • 2019-12-11 - Coordinated public release of advisory
CREDIT Jeong Oh Kyea(@kkokkokye) of THEORI
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