CVE-2020-27216: Vulnerability Overview and Mitigation

CVE-2020-27216 was published on 2020-11-25T16:00:00. This vulnerability affects Eclipse Jetty, leading to potential local privilege escalation.

Understanding CVE-2020-27216

This section provides an overview of CVE-2020-27216, detailing the impact, technical aspects, and affected systems.

What is CVE-2020-27216?

CVE-2020-27216 is a security flaw in Eclipse Jetty versions 1.0 through 9.4.32.v20200930, 10.0.0.alpha1 through 10.0.0.beta2, and 11.0.0.alpha1 through 11.0.0.beta2. On Unix-like systems, the system's temporary directory is shared between all users on that system. A collocated user can observe the process of creating a temporary subdirectory in the shared temporary directory and race to complete the creation of the temporary subdirectory. If the attacker wins the race, they will have read and write permissions to the subdirectory used to unpack web applications, including their WEB-INF/lib jar files and JSP files. If any code is ever executed out of this temporary directory, this can lead to a local privilege escalation vulnerability.

The Impact of CVE-2020-27216

The highest threat from this vulnerability is local privilege escalation, as it allows attackers to gain unauthorized read and write permissions in the temporary subdirectory used by web applications.

Technical Details of CVE-2020-27216

This section delves into the technical aspects of the vulnerability, including its description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability arises from the shared temporary directory on Unix-like systems. Attackers can exploit this by racing to create a temporary subdirectory, gaining unauthorized access to the subdirectory used by web applications.

Affected Systems and Versions

The following systems and versions are affected by CVE-2020-27216:

Eclipse Jetty
affected: 1.0 to 9.4.32.v20200930
affected: 10.0.0.alpha1 to 10.0.0.beta2
affected: 11.0.0.alpha1 to 11.0.0.beta2

Exploitation Mechanism

The exploitation involves racing to create a temporary subdirectory in the shared temporary directory, allowing attackers to gain unauthorized access to the subdirectory used by web applications.

Mitigation and Prevention

To mitigate and prevent this vulnerability, it is essential to follow the recommended steps and best practices.

Immediate Steps to Take

Update to the latest version of Eclipse Jetty.
Review and apply security patches provided by The Eclipse Foundation.

Long-Term Security Practices

Regularly update web applications and dependencies to the latest versions.
Implement secure coding practices to prevent such vulnerabilities.
Regularly review and apply security patches.

Patching and Updates

The Eclipse Foundation has released updates to address this vulnerability. Users should ensure that their systems are updated to the latest versions to mitigate the risk.