External risk intelligence

Microsoft Windows Font Library Remote Code Execution Vulnerability.

CVE advisoryKnown Exploit

CVE-2020-0938

A vulnerability in the Windows Adobe Type Manager Library allows remote code execution via crafted font files. This poses a risk to system integrity and confidentiality. Affected organizations should identify and remediate systems.

1Halo Surface Signal

Out-of-bounds Write

Microsoft Windows 10 1507

r2

External exposure likelihood

Halo Surface Signal score for CVE-2020-0938

The vulnerability involves local handling of specially crafted font files within the Windows Adobe Type Manager Library. It is not a network-reachable service, gateway, or internet-facing application; successful exploitation typically requires the local interaction of opening a malicious file or document, making public-internet exposure of the vulnerable surface very unlikely.

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability in the Windows Adobe Type Manager Library allows for remote code execution when processing specially crafted font files. For most Windows systems, successful exploitation enables attackers to execute code remotely. This flaw presents a risk to the integrity and confidentiality of affected systems.

  • Vulnerable component: Windows Adobe Type Manager Library
  • Core weakness: Improper font file handling
  • Main business impact: Remote code execution

Attack Path

How an attacker could exploit the issue

A vulnerability exists within the Windows Adobe Type Manager Library, which improperly handles specially crafted multi-master fonts. For systems other than Windows 10, successful exploitation allows an attacker to execute code remotely. For Windows 10 systems, an attacker could execute code within an AppContainer sandbox with limited privileges.

  • Exposure condition: Local handling of crafted font files.
  • Attacker starting point: Requires user interaction.
  • Trigger and result: Executes code, potentially remotely or in a sandbox.

Live Threat

Current exploitation, exposure, and threat context

A vulnerability in the Windows Adobe Type Manager Library could allow an attacker to execute code remotely. This occurs when a specially crafted font file is improperly handled. For systems other than Windows 10, successful exploitation can lead to remote code execution. The Common Vulnerabilities and Exposures (CVE) catalog lists this vulnerability as HIGH severity.

  • Attacker skill level: Moderate.
  • Required access: Local access or user interaction.
  • Business risk: High urgency.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability may allow an attacker to execute arbitrary code on an affected system. Organizations should take steps to identify systems with exposure to this vulnerability, reduce that exposure, apply the vendor-provided fix, validate the successful application of the fix, and monitor for related activities. This vulnerability has been observed in the wild and is considered to be at high risk.

  • Find affected assets.
  • Reduce exposure or isolate risk.
  • Fix, verify, and monitor.

Frequently asked questions

What is the primary software component affected by CVE-2020-0938 and what type of vulnerability does it present?

CVE-2020-0938 affects the Windows Adobe Type Manager Library. It is a remote code execution vulnerability that occurs when the library improperly handles specially crafted multi-master fonts in the Adobe Type 1 PostScript format.

What is the core weakness and potential impact of the CVE-2020-0938 vulnerability on different Windows systems?

The core weakness is improper handling of font files, specifically a CWE-787 (Buffer past end of buffer) type. For systems other than Windows 10, exploitation allows remote code execution. On Windows 10, an attacker can execute code within an AppContainer sandbox with limited privileges and capabilities.

How is the CVE-2020-0938 vulnerability triggered, and what is the scope of impact for attackers?

The vulnerability is triggered by a specially crafted multi-master font file. Successful exploitation on systems other than Windows 10 allows an attacker to execute code remotely. For Windows 10, the scope is limited to code execution within an AppContainer sandbox.

How does the Halo Surface Signal classify the exposure risk for CVE-2020-0938, and why?

Halo classifies this CVE as 'internal' because the CVSS v3.1 attack vector is Local (AV:L). This means the vulnerability requires local handling of font files and is not a network-reachable service, making public-internet exposure very unlikely.

What practical steps should organizations take to address the CVE-2020-0938 vulnerability?

Organizations should identify affected assets, reduce exposure, apply vendor-provided fixes, verify successful patching, and monitor for related activities. This vulnerability is rated as HIGH severity and requires urgent attention.

References