CVE-2018-18398 : Security Advisory and Response

Xfce Thunar 1.6.15, when used with Xfce 4.12, has a vulnerability related to the IBus-Unikey input method, potentially leading to an out-of-bounds read and SEGV.

Understanding CVE-2018-18398

This CVE involves a specific issue in Xfce Thunar 1.6.15 when interacting with Xfce 4.12, affecting the handling of the IBus-Unikey input method during file searches.

What is CVE-2018-18398?

An out-of-bounds read vulnerability in Xfce Thunar 1.6.15, in conjunction with Xfce 4.12, allows a local user to exploit the IBus-Unikey input method, potentially leading to a SEGV.

The Impact of CVE-2018-18398

The vulnerability poses a risk of out-of-bounds read and SEGV, which could be exploited by a local user to create files in the /tmp directory before the targeted individual uses the input method.

Technical Details of CVE-2018-18398

This section provides more technical insights into the vulnerability.

Vulnerability Description

Xfce Thunar 1.6.15 mishandles the IBus-Unikey input method during file searches in the File Manager, resulting in an out-of-bounds read and potential SEGV.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions: 1.6.15

Exploitation Mechanism

The vulnerability can be exploited by a local user to manipulate the IBus-Unikey input method, creating files in the /tmp directory before the intended user engages with the input method.

Mitigation and Prevention

To address CVE-2018-18398, consider the following steps:

Immediate Steps to Take

Monitor for any unauthorized file creation in the /tmp directory.
Restrict access to the IBus-Unikey input method.

Long-Term Security Practices

Regularly update Xfce Thunar and Xfce to the latest versions.
Implement proper input method handling protocols to prevent similar vulnerabilities.

Patching and Updates

Ensure timely installation of patches and updates provided by Xfce to mitigate the vulnerability.