Privilege escalation in AppX Deployment Service in Microsoft Windows

Published: 2019-07-10

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2019-1129 CVE-2019-1130
CWE-ID	CWE-264
Exploitation vector	Local
Public exploit	Vulnerability #1 is being exploited in the wild. Vulnerability #2 is being exploited in the wild.
Vulnerable software Subscribe	Windows Operating systems & Components / Operating system Windows Server Operating systems & Components / Operating system
Vendor	Microsoft

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU19120

Risk: Low

CVSSv3.1: 8.4 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2019-1129

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to the way Windows AppX Deployment Service (AppXSVC) handles hard links. A local user can create a hard link to a critical file on the system and gain full control over that file.

Successful exploitation of the vulnerability may allow an attacker to gain elevated privileges.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Windows: 10 1703 - 10 1903

Windows Server: 2019 - 2019 1903

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1129

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

2) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU19121