CVE-2017-11742 : Vulnerability Insights and Analysis

CVE-2017-11742 was published on July 30, 2017, and affects the libexpat library's xmlparse.c file, specifically versions 2.2.1 and 2.2.2 on Windows. This vulnerability allows local individuals to gain elevated privileges by exploiting a DLL hijacking issue.

Understanding CVE-2017-11742

This CVE entry highlights a security flaw in the libexpat library that can be exploited by placing a malicious ADVAPI32.DLL file in the current working directory.

What is CVE-2017-11742?

The vulnerability in the writeRandomBytes_RtlGenRandom function of the libexpat library's xmlparse.c file allows local attackers to escalate their privileges by manipulating the DLL loading process.

The Impact of CVE-2017-11742

The vulnerability enables attackers to execute arbitrary code with elevated privileges, posing a significant security risk to affected systems.

Technical Details of CVE-2017-11742

This section delves into the specific technical aspects of the CVE.

Vulnerability Description

The writeRandomBytes_RtlGenRandom function in Expat 2.2.1 and 2.2.2 on Windows permits local users to gain privileges through a malicious ADVAPI32.DLL in the current working directory due to an untrusted search path, known as DLL hijacking.

Affected Systems and Versions

Library: libexpat
Versions: 2.2.1 and 2.2.2
Operating System: Windows

Exploitation Mechanism

Attackers can exploit this vulnerability by placing a crafted ADVAPI32.DLL file in the same directory as the application that utilizes the libexpat library, leading to the execution of arbitrary code.

Mitigation and Prevention

Protecting systems from CVE-2017-11742 requires immediate actions and long-term security practices.

Immediate Steps to Take

Remove unnecessary or unused DLL files from the system.
Implement secure coding practices to avoid DLL hijacking vulnerabilities.

Long-Term Security Practices

Regularly update software and libraries to patched versions.
Conduct security assessments to identify and remediate DLL hijacking vulnerabilities.

Patching and Updates

Apply patches provided by the software vendor to address the vulnerability.