CVE-2020-15396 Explained : Impact and Mitigation

In HylaFAX+ through 7.0.2 and HylaFAX Enterprise, a vulnerability exists that could allow a local attacker to escalate privileges to root by exploiting the faxsetup utility.

Understanding CVE-2020-15396

This CVE describes a privilege escalation vulnerability in HylaFAX+ and HylaFAX Enterprise through version 7.0.2.

What is CVE-2020-15396?

The vulnerability arises from the faxsetup utility in HylaFAX+ and HylaFAX Enterprise, which improperly calls chown on files in user-owned directories. This flaw can be exploited by a local attacker to elevate their privileges to root by winning a race condition.

The Impact of CVE-2020-15396

The impact of this vulnerability is that a local attacker can potentially gain root privileges on the affected system, leading to unauthorized access and control.

Technical Details of CVE-2020-15396

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability allows a local attacker to exploit the faxsetup utility in HylaFAX+ and HylaFAX Enterprise, leading to privilege escalation to root.

Affected Systems and Versions

HylaFAX+ through version 7.0.2
HylaFAX Enterprise

Exploitation Mechanism

By manipulating the chown function on files in user-owned directories, a local attacker can escalate their privileges to root by exploiting a race condition.

Mitigation and Prevention

To address CVE-2020-15396, follow these mitigation strategies.

Immediate Steps to Take

Apply the vendor-provided patches promptly.
Restrict access to the faxsetup utility to authorized users only.
Monitor system logs for any suspicious activities.

Long-Term Security Practices

Regularly update and patch all software and systems.
Implement the principle of least privilege to limit user access rights.
Conduct regular security audits and assessments to identify and remediate vulnerabilities.

Patching and Updates

Update HylaFAX+ and HylaFAX Enterprise to versions that contain fixes for this vulnerability.