CVE-2017-12109 : Exploit Details and Defense Strategies

A vulnerability in libxls 1.4 allows for remote code execution through a crafted XLS file.

Understanding CVE-2017-12109

This CVE involves an integer overflow flaw in the xls_preparseWorkSheet function of libxls 1.4, enabling attackers to execute remote code.

What is CVE-2017-12109?

The vulnerability in libxls 1.4 arises from an integer overflow issue in the xls_preparseWorkSheet function when processing a MULRK record. This flaw can be exploited by creating a malicious XLS file to manipulate memory and execute remote code.

The Impact of CVE-2017-12109

The vulnerability has a CVSS base score of 8.8 (High severity) with high impacts on confidentiality, integrity, and availability. It requires no special privileges from the attacker and user interaction is necessary.

Technical Details of CVE-2017-12109

The technical aspects of the vulnerability in libxls 1.4.

Vulnerability Description

The xls_preparseWorkSheet function in libxls 1.4 has an integer overflow flaw that can be exploited by creating a specially crafted XLS file.

Affected Systems and Versions

Product: libxls
Vendor: libxls
Versions Affected: 1.4 readxl package 1.0.0 for R (tested using Microsoft R 4.3.1)

Exploitation Mechanism

Attackers can exploit this vulnerability by sending a malicious XLS file to trigger the integer overflow flaw.

Mitigation and Prevention

Ways to mitigate and prevent exploitation of CVE-2017-12109.

Immediate Steps to Take

Update libxls to a patched version that addresses the integer overflow vulnerability.
Avoid opening XLS files from untrusted or unknown sources.

Long-Term Security Practices

Regularly update software and libraries to the latest versions to patch known vulnerabilities.

Patching and Updates

Stay informed about security updates for libxls and apply patches promptly to protect against potential exploits.