CVE-2018-12615 : What You Need to Know

Phusion Passenger before 5.3.2 has a vulnerability in the switchGroup() function that can lead to uninitialized memory selection of supplementary groups.

Understanding CVE-2018-12615

This CVE identifies a flaw in Phusion Passenger versions prior to 5.3.2 that affects the correct assignment of supplementary groups, potentially resulting in security issues.

What is CVE-2018-12615?

The issue lies in the switchGroup() function in Phusion Passenger's ExecHelperMain.cpp file, where the gidset (group set) is not assigned correctly. This can allow uninitialized memory to select supplementary groups, posing a risk when reducing privileges.

The Impact of CVE-2018-12615

The vulnerability could be exploited to manipulate group privileges, potentially leading to unauthorized access or privilege escalation within affected systems.

Technical Details of CVE-2018-12615

Phusion Passenger before version 5.3.2 is susceptible to the following technical aspects:

Vulnerability Description

The switchGroup() function in ExecHelperMain.cpp does not correctly assign the group set (gidset), allowing uninitialized memory to select supplementary groups, which can compromise system security.

Affected Systems and Versions

Product: Phusion Passenger
Vendor: Phusion
Versions Affected: Prior to 5.3.2

Exploitation Mechanism

The vulnerability can be exploited by an attacker to manipulate group privileges, potentially gaining unauthorized access or escalating privileges within the system.

Mitigation and Prevention

To address CVE-2018-12615, consider the following steps:

Immediate Steps to Take

Update Phusion Passenger to version 5.3.2 or later to mitigate the vulnerability.
Monitor system logs for any unusual group privilege changes.

Long-Term Security Practices

Regularly review and update software dependencies to prevent similar vulnerabilities.
Implement the principle of least privilege to restrict access rights for users and processes.

Patching and Updates

Apply security patches and updates promptly to ensure the system is protected against known vulnerabilities.