CVE-2018-19044 : Exploit Details and Defense Strategies

A vulnerability in keepalived version 2.0.8 allowed local users to overwrite arbitrary files by creating symbolic links in specific scenarios.

Understanding CVE-2018-19044

This CVE entry describes a security issue in keepalived version 2.0.8 that could be exploited by local users.

What is CVE-2018-19044?

The vulnerability in keepalived version 2.0.8 involved the failure to verify pathnames with symbolic links when writing data to a temporary file during PrintData or PrintStats operation.

The Impact of CVE-2018-19044

Exploitation of this vulnerability by local users is possible if the setting fs.protected_symlinks is disabled, allowing the overwrite of any file by creating a symlink from specific paths to critical system files.

Technical Details of CVE-2018-19044

This section provides more technical insights into the vulnerability.

Vulnerability Description

Keepalived 2.0.8 did not check for pathnames with symlinks when writing data to a temporary file upon a call to PrintData or PrintStats.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Version: 2.0.8 (affected)

Exploitation Mechanism

Local users could exploit this vulnerability by disabling fs.protected_symlinks and creating a symlink from /tmp/keepalived.data or /tmp/keepalived.stats to /etc/passwd.

Mitigation and Prevention

Protecting systems from this vulnerability requires specific actions.

Immediate Steps to Take

Enable fs.protected_symlinks to prevent symlink attacks.
Regularly monitor and restrict access to critical system files.

Long-Term Security Practices

Implement the principle of least privilege to limit user capabilities.
Conduct regular security audits and vulnerability assessments.

Patching and Updates

Apply patches or updates provided by the software vendor to address this vulnerability.