Advisory Details

April 15th, 2019

Microsoft Windows AppX Deployment Service Hard Link Privilege Escalation Vulnerability

ZDI-19-360
ZDI-CAN-7753

CVE ID CVE-2019-0841
CVSS SCORE 7.3, (AV:L/AC:L/PR:L/UI:R/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 vulnerable 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 weaken the ACL of a chosen file. An attacker can leverage this vulnerability to escalate privileges to resources normally protected from the current user or app.

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-2019-0841
DISCLOSURE TIMELINE
  • 2018-12-29 - Vulnerability reported to vendor
  • 2019-04-15 - Coordinated public release of advisory
CREDIT Anonymous
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