CVE-2017-12840 : What You Need to Know

CVE-2017-12840, related to the DESLock+ client application, involves a locally exploitable heap-based buffer overflow vulnerability in a kernel driver. Learn about the impact, technical details, and mitigation steps.

Understanding CVE-2017-12840

What is CVE-2017-12840?

The DESLock+ client application 4.8.16 and earlier versions contain a kernel driver, DLMFENC.sys, with a heap-based buffer overflow vulnerability. This vulnerability arises when handling a specific IOCTL message, leading to a potential security risk.

The Impact of CVE-2017-12840

The vulnerability allows for a locally exploitable heap-based buffer overflow, potentially enabling attackers to execute arbitrary code or crash the system.

Technical Details of CVE-2017-12840

Vulnerability Description

The kernel driver, DLMFENC.sys, fails to allocate sufficient memory for a user-supplied string, causing a buffer overflow when copying the string into a fixed-size buffer.

Affected Systems and Versions

Product: DESLock+ client application 4.8.16 and earlier
Vendor: Not applicable
Versions: Not applicable

Exploitation Mechanism

The vulnerability occurs when handling an IOCTL message with the code 0x0FA4204
The kernel driver does not allocate enough memory for the user-provided string
The string is copied into a buffer of constant size, leading to an overflow situation
Access to the kernel driver is through an obfuscated interface

Mitigation and Prevention

Immediate Steps to Take

Disable or remove the vulnerable application or driver if possible
Monitor for any unusual system behavior or crashes

Long-Term Security Practices

Regularly update software and drivers to patched versions
Implement strong access controls and least privilege principles

Patching and Updates

Check for security advisories from the vendor
Apply patches or updates provided by the vendor