CVE Vulnerabilities

CVE-2019-0986

Improper Link Resolution Before File Access ('Link Following')

Published: Jun 12, 2019 | Modified: May 20, 2025
CVSS 3.x
7.1
HIGH
Source:
NVD
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
CVSS 2.x
3.6 LOW
AV:L/AC:L/Au:N/C:N/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

An elevation of privilege vulnerability exists when the Windows User Profile Service (ProfSvc) improperly handles symlinks. An attacker who successfully exploited this vulnerability could delete files and folders in an elevated context. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and delete files or folders of their choosing. The security update addresses the vulnerability by correcting how the Windows User Profile Service handles symlinks.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Name Vendor Start Version End Version
Windows_10 Microsoft - (including) - (including)
Windows_10 Microsoft 1607 (including) 1607 (including)
Windows_10 Microsoft 1703 (including) 1703 (including)
Windows_10 Microsoft 1709 (including) 1709 (including)
Windows_10 Microsoft 1803 (including) 1803 (including)
Windows_10 Microsoft 1809 (including) 1809 (including)
Windows_10 Microsoft 1903 (including) 1903 (including)
Windows_7 Microsoft –sp1 (including) –sp1 (including)
Windows_8.1 Microsoft - (including) - (including)
Windows_rt_8.1 Microsoft - (including) - (including)
Windows_server_2008 Microsoft –sp2 (including) –sp2 (including)
Windows_server_2008 Microsoft r2-sp1 (including) r2-sp1 (including)
Windows_server_2012 Microsoft - (including) - (including)
Windows_server_2012 Microsoft r2 (including) r2 (including)
Windows_server_2016 Microsoft - (including) - (including)
Windows_server_2016 Microsoft 1803 (including) 1803 (including)
Windows_server_2016 Microsoft 1903 (including) 1903 (including)
Windows_server_2019 Microsoft - (including) - (including)

Potential Mitigations

  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

References