CVE-2017-5618 : Security Advisory and Response

CVE-2017-5618 was published on January 24, 2017, and affects GNU screen versions before 4.5.1. The vulnerability allows local users to modify files and gain root privileges due to inadequate validation of logfile permissions.

Understanding CVE-2017-5618

This CVE entry pertains to a security flaw in GNU screen that can be exploited by local users to escalate privileges.

What is CVE-2017-5618?

CVE-2017-5618 is a vulnerability in GNU screen versions prior to 4.5.1 that enables unauthorized users to alter files and potentially achieve root access on the system.

The Impact of CVE-2017-5618

The vulnerability in GNU screen could lead to local users gaining root privileges, posing a significant security risk to affected systems.

Technical Details of CVE-2017-5618

This section provides more in-depth technical information about the CVE.

Vulnerability Description

Before version 4.5.1, GNU screen allows local users to modify arbitrary files, leading to potential root privilege escalation due to improper logfile permission checks.

Affected Systems and Versions

Product: GNU screen
Vendor: GNU
Versions affected: All versions before 4.5.1

Exploitation Mechanism

The vulnerability arises from the lack of proper validation of logfile permissions, enabling unauthorized users to manipulate files and gain elevated privileges.

Mitigation and Prevention

Protecting systems from CVE-2017-5618 requires immediate actions and long-term security measures.

Immediate Steps to Take

Update GNU screen to version 4.5.1 or newer to mitigate the vulnerability.
Restrict access to sensitive files and directories to authorized users only.

Long-Term Security Practices

Implement the principle of least privilege to limit user access rights.
Regularly monitor and audit file permissions and user activities to detect unauthorized changes.

Patching and Updates

Apply security patches promptly to address known vulnerabilities and enhance system security.