External risk intelligence

Windows BITS Privilege Escalation Vulnerability

CVE advisoryKnown Exploit

CVE-2020-0787

A vulnerability in Windows' Background Intelligent Transfer Service allows for privilege escalation when symbolic links are improperly handled. This impacts organizations by enabling unauthorized system control and code execution. The risk is localized as it requires direct system access.

1Halo Surface Signal

Microsoft Windows 10 1507

r2

External exposure likelihood

Halo Surface Signal score for CVE-2020-0787

This vulnerability affects the Windows Background Intelligent Transfer Service (BITS), which is a local operating system component. Exploitation requires local access to the system to manipulate symbolic links, making it inherently a local-only concern rather than a network-reachable or public-facing service.

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability in the Windows Background Intelligent Transfer Service (BITS) could allow an attacker to gain elevated privileges on a system. This flaw arises from how BITS handles symbolic links. Exploitation of this issue could lead to unauthorized system access and control.

  • Vulnerable component: Windows Background Intelligent Transfer Service (BITS)
  • Core weakness: Improper handling of symbolic links
  • Main business impact: Unauthorized system access and control

Attack Path

How an attacker could exploit the issue

The Windows Background Intelligent Transfer Service (BITS) has a vulnerability that could allow an attacker to gain elevated privileges. This occurs when BITS does not properly manage symbolic links. An attacker could leverage this to execute arbitrary code on a targeted system.

  • Local system access required.
  • Attacker manipulates symbolic links.
  • Attacker achieves code execution.

Live Threat

Current exploitation, exposure, and threat context

An elevation of privilege vulnerability in the Windows Background Intelligent Transfer Service (BITS) could allow an attacker to gain system-level privileges. This occurs when BITS improperly handles symbolic links. Successful exploitation could lead to unauthorized code execution with elevated permissions.

  • Likely attacker skill level: Low
  • Required access or conditions: Local access, user interaction
  • Business risk or urgency: High

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

An elevation of privilege vulnerability exists within the Windows Background Intelligent Transfer Service (BITS) due to improper handling of symbolic links. Successful exploitation could allow an attacker to execute arbitrary code with system-level privileges. This vulnerability impacts organizations by potentially compromising system integrity and data confidentiality. The exploitability of this vulnerability requires local access to the system, mitigating broad network exposure.

  • Identify affected systems.
  • Reduce exposure or isolate risk.
  • Apply vendor fixes and validate.
  • Monitor for related activity.

Frequently asked questions

What is the Windows Background Intelligent Transfer Service (BITS)?

Windows Background Intelligent Transfer Service (BITS) is a Windows component used for transferring files between a client computer and a server. It allows applications to download or upload files in the background, even if the user is not logged in or the application is closed. It is often used by Windows Update and other Microsoft services for efficient data transfer.

How does CVE-2020-0787 enable privilege escalation?

CVE-2020-0787 is an elevation of privilege vulnerability. It stems from how the Windows Background Intelligent Transfer Service (BITS) improperly handles symbolic links. By exploiting this weakness, an attacker could gain higher privileges on the affected system than they would normally have.

What conditions must be met for an attacker to trigger this vulnerability?

Exploiting this vulnerability requires an attacker to have local access to the affected system. They need to manipulate symbolic links in a specific way that the Windows Background Intelligent Transfer Service (BITS) does not handle correctly. User interaction is also a condition for triggering the bug.

Who should be concerned about CVE-2020-0787?

Organizations with Windows systems that use the Background Intelligent Transfer Service should be concerned. Because exploitation requires local access, this vulnerability is considered internal. This means an attacker would first need to gain some level of access to a machine before they could exploit this flaw to gain higher privileges.

What is the first step for managing this CVE threat?

The initial step for managing this threat is to identify all systems running affected versions of Windows. After identification, it is crucial to apply security updates provided by Microsoft to remediate the vulnerability. Monitoring for any suspicious activity related to file transfers or system privilege changes is also recommended.

References