CVE-2020-0787 Microsoft Windows Background Intelligent Transfer Service (BITS) Improper Privilege Management Vulnerability
Microsoft Windows BITS is vulnerable to to a privilege elevation vulnerability if it improperly handles symbolic links. An actor can exploit this vulnerability to execute arbitrary code with system-level privileges.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 28 Jan 2022.
- CISA lists it as known to be used in ransomware campaigns.
- Rated High severity (CVSS 7.8, scored by CISA).
- It has been in the catalogue for 1,743 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
An elevation of privilege vulnerability exists when the Windows Background Intelligent Transfer Service (BITS) improperly handles symbolic links, aka 'Windows Background Intelligent Transfer Service Elevation of Privilege Vulnerability'.
Affected Versions
| Product | Versions |
|---|---|
| Microsoft Windows | 10 Version 1803 for 32-bit Systems 10 Version 1803 for x64-based Systems 10 Version 1803 for ARM64-based Systems 10 Version 1809 for 32-bit Systems 10 Version 1809 for x64-based Systems 10 Version 1809 for ARM64-based Systems |
| Microsoft Windows Server | version 1803 (Core Installation) 2019 2019 (Core installation) 2016 2016 (Core installation) 2008 for 32-bit Systems Service Pack 2 |
| Microsoft Windows 10 Version 1909 for 32-bit Systems | unspecified |
| Microsoft Windows 10 Version 1909 for x64-based Systems | unspecified |
| Microsoft Windows 10 Version 1909 for ARM64-based Systems | unspecified |
| Microsoft Windows Server, version 1909 (Server Core installation) | unspecified |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Microsoft Windows. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
- 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
Vendor Advisories
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
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