CVE-2017-12108 : Security Advisory and Response

A vulnerability in the xls_preparseWorkSheet function of libxls 1.4 can lead to remote code execution due to an integer overflow when processing a MULBLANK record. Attackers can exploit this by sending a malicious XLS file.

Understanding CVE-2017-12108

This CVE involves a high-severity vulnerability in libxls 1.4 that allows attackers to execute remote code by manipulating memory through a specially crafted XLS file.

What is CVE-2017-12108?

The vulnerability in libxls 1.4 arises from an integer overflow in the xls_preparseWorkSheet function when handling a MULBLANK record. This flaw enables attackers to potentially execute remote code by exploiting memory corruption.

The Impact of CVE-2017-12108

The impact of this CVE is rated as high, with a CVSS base score of 8.8. The confidentiality, integrity, and availability of affected systems are all at risk, with no privileges required for exploitation.

Technical Details of CVE-2017-12108

This section provides more technical insights into the vulnerability.

Vulnerability Description

An integer overflow vulnerability in the xls_preparseWorkSheet function of libxls 1.4 allows for remote code execution through memory manipulation using a specially crafted XLS file.

Affected Systems and Versions

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

Exploitation Mechanism

The vulnerability can be exploited by sending a carefully crafted XLS file that triggers the integer overflow in the xls_preparseWorkSheet function, leading to memory corruption and potential remote code execution.

Mitigation and Prevention

To address CVE-2017-12108, follow these mitigation strategies:

Immediate Steps to Take

Apply security patches provided by the vendor promptly.
Avoid opening XLS files from untrusted or unknown sources.
Implement network-level protections to detect and block malicious XLS files.

Long-Term Security Practices

Regularly update software and applications to patch known vulnerabilities.
Conduct security training for users to recognize and report suspicious files or activities.

Patching and Updates

Stay informed about security updates released by libxls.
Monitor security advisories and apply patches as soon as they are available.