Privilege escalation in AppX Deployment Service in Microsoft Windows

Published: 2019-07-10 | Updated: 2019-07-10
Severity 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 Public exploit code for vulnerability #1 is available.
Vulnerable software Windows Subscribe
Windows Server
Vendor Microsoft

Security Advisory

1) Permissions, Privileges, and Access Controls

Severity: Low

CVSSv3: 7.9 [CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C] [PCI]

CVE-ID: CVE-2019-1129

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

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 1709, 10 1803, 10 1809, 10 1903

Windows Server: 1803, 1903, 2019

CPE External links

https://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?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

2) Permissions, Privileges, and Access Controls

Severity: Low

CVSSv3: 7.7 [CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2019-1130

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

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: 8.1, 10, 10 1607, 10 1703, 10 1709, 10 1803, 10 1809, 10 1903, RT 8.1

Windows Server: 1803, 1903, 2012, 2012 R2, 2016, 2019

CPE External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1130

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?

No. We are not aware of malware exploiting this vulnerability.