CVE-2017-6638 : Security Advisory and Response

A weakness has been identified in the way DLL files are loaded when using Cisco AnyConnect Secure Mobility Client for Windows, potentially allowing an authenticated, local attacker to escalate privileges. This vulnerability affects all versions of Cisco AnyConnect Secure Mobility Client for Windows released before 4.4.02034.

Understanding CVE-2017-6638

This CVE involves a local privilege escalation vulnerability in Cisco AnyConnect Secure Mobility Client for Windows.

What is CVE-2017-6638?

The vulnerability arises from improper validation of DLL file paths and names, enabling a local attacker to execute commands with SYSTEM account privileges by installing a malicious DLL file.

The Impact of CVE-2017-6638

The vulnerability could be exploited by an authenticated, local attacker with valid user credentials to execute arbitrary commands on the host system with elevated privileges.

Technical Details of CVE-2017-6638

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability in Cisco AnyConnect Secure Mobility Client for Windows allows an attacker to install and execute an executable file with SYSTEM account privileges due to inadequate validation of DLL file paths and names.

Affected Systems and Versions

All versions of Cisco AnyConnect Secure Mobility Client for Windows released before 4.4.02034 are impacted by this vulnerability.

Exploitation Mechanism

To exploit this vulnerability, an attacker needs to create a malicious DLL file and install it in a specific system directory. By doing so, the attacker can run commands on the host system with SYSTEM account privileges.

Mitigation and Prevention

Protecting systems from CVE-2017-6638 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Cisco AnyConnect Secure Mobility Client for Windows to version 4.4.02034 or later to mitigate the vulnerability.
Monitor for any unauthorized DLL file installations on the system.

Long-Term Security Practices

Implement the principle of least privilege to restrict user access and limit potential damage from privilege escalation attacks.
Regularly review and update security policies and procedures to address emerging threats.

Patching and Updates

Apply security patches and updates provided by Cisco to address vulnerabilities and enhance the security of the AnyConnect Secure Mobility Client for Windows.