CVE-2017-11747 : Vulnerability Insights and Analysis

Tinyproxy 1.8.4 and earlier versions generate a file that could potentially allow local users to terminate processes. Learn about the impact, technical details, and mitigation steps.

Understanding CVE-2017-11747

What is CVE-2017-11747?

In versions 1.8.4 and earlier of Tinyproxy, a file called "tinyproxy.pid" is created in the "/run/tinyproxy/" directory when switching to a non-root account, potentially enabling local users to terminate processes.

The Impact of CVE-2017-11747

The vulnerability could allow local users to exploit their access to a non-root account and modify the tinyproxy.pid file, leading to the termination of arbitrary processes.

Technical Details of CVE-2017-11747

Vulnerability Description

The main.c file in Tinyproxy creates the tinyproxy.pid file after dropping privileges to a non-root account, allowing local users to kill processes by modifying this file.

Affected Systems and Versions

Product: Tinyproxy
Versions affected: 1.8.4 and earlier

Exploitation Mechanism

Local users can exploit their access to the non-root account and modify the tinyproxy.pid file before a root script executes a command like "kill

cat /run/tinyproxy/tinyproxy.pid

".

Mitigation and Prevention

Immediate Steps to Take

Update Tinyproxy to the latest version that addresses this vulnerability.
Monitor and restrict access to the tinyproxy.pid file.

Long-Term Security Practices

Implement the principle of least privilege to limit user access.
Regularly review and update file permissions to prevent unauthorized modifications.

Patching and Updates

Regularly check for security updates and patches for Tinyproxy to ensure protection against known vulnerabilities.