Advisory Details

September 10th, 2019

Microsoft Windows AppX Deployment Service Junction Arbitrary File Deletion Vulnerability

ZDI-19-803
ZDI-CAN-8602

CVE ID CVE-2019-1253
CVSS SCORE 6.1, (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H)
AFFECTED VENDORS Microsoft
AFFECTED PRODUCTS Windows
VULNERABILITY DETAILS

This vulnerability allows local attackers to delete arbitrary files 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 junction, an attacker can abuse the service to delete files in an incorrect location. An attacker can leverage this vulnerability to delete files 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-2019-1253
DISCLOSURE TIMELINE
  • 2019-05-08 - Vulnerability reported to vendor
  • 2019-09-10 - Coordinated public release of advisory
CREDIT Nabeel Ahmed of Dimension Data Belgium
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