External risk intelligence

Wondershare Dr.Fone Remote Code Execution Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2021-44596

The vulnerable service is a local utility component (InstallAssistService.exe) bundled with desktop software. While it communicates via UDP, such services are typically intended for local machine or LAN operations rather than exposure to the public internet. Public internet exposure for this specific type of desktop-based support service is uncommon.

Remote Code Execution

Wondershare Dr Fone

2021-12-06

Halo Surface Signal: 2 out of 5 — less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A design flaw in Wondershare Dr. Fone software allows an unauthenticated attacker to remotely execute malicious code and gain system-level privileges. The vulnerability resides in a service that communicates over UDP and lacks proper validation, potentially enabling unauthorized control over affected systems.

Flaw allows remote code execution.
Critical vulnerability with system-level access.
Confirm relevance and exposure of the software.

Attack Path

How an attacker could exploit the issue

An attacker can remotely execute code and gain system privileges by exploiting a flaw in Wondershare Dr. Fone's InstallAssistService.exe. This service, running with elevated permissions, can be manipulated by an unauthenticated user sending specially crafted UDP messages to execute arbitrary code without validation.

Requires network access.
Triggered by sending UDP messages.
Risk of remote code execution and privilege escalation.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an unauthenticated remote attacker to execute arbitrary code with SYSTEM privileges on a system running the affected software. The attack targets the `InstallAssistService.exe` service, which runs with high privileges and lacks sufficient validation of UDP communications.

Remote code execution with SYSTEM privileges.
Exploits unauthenticated UDP communication.
Full system compromise is possible.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Dr.Fone product, specifically its InstallAssistService.exe component running with SYSTEM privileges, is susceptible to remote code execution. This vulnerability allows unauthenticated users to execute malicious code by communicating over UDP with the service without validation. Initial actions should focus on identifying all instances of Dr.Fone within the environment, determining their reachability and business criticality, locating the accountable system owners, and then developing a risk-based remediation plan.

Identify Dr.Fone instances and owners.
Verify service reachability and criticality.
Plan targeted remediation and vendor coordination.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Wondershare Dr. Fone?

Wondershare Dr. Fone is a utility software suite designed for mobile device management, including data recovery, system repair, and file transfer. It often includes background support services, such as the InstallAssistService.exe component, to manage updates or auxiliary operations on Windows systems where the software is installed.

What does CVE-2021-44596 mean for security?

This vulnerability is a design flaw that allows unauthorized remote code execution. Because the affected service runs with high-level SYSTEM privileges, a successful interaction allows an attacker to bypass security checks and execute arbitrary commands with full control over the host operating system.

How is this vulnerability triggered?

An attacker triggers this flaw by sending specially crafted UDP network packets to the InstallAssistService.exe component. The service fails to validate these inputs, allowing malicious instructions to be processed. Simply using the Dr. Fone interface for standard tasks does not trigger the bug; it requires specifically formed network traffic directed at this background service.

Is my system at risk?

According to Halo Surface Signal, this risk is generally unlikely because InstallAssistService.exe is a local desktop component typically designed for internal or LAN use. It is not intended to be exposed to the public internet. Systems are most relevant if this specific service has been inadvertently configured to accept traffic from untrusted or external networks.

What should I do if I run Dr. Fone?

Begin by identifying all systems in your environment where Dr. Fone is installed. Coordinate with system owners to verify if the InstallAssistService.exe process is reachable over your network and assess its business necessity. Prioritize restricting network access to the service and contact the vendor for official software updates to resolve the underlying design flaw.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.