In today's ever-evolving world of technology, ensuring the security of our applications and systems is of utmost importance. It is crucial to stay updated on the latest vulnerabilities and exploits to protect your applications from potential threats. CVE-2023-39155 is one such vulnerability that affects the Jenkins Chef Identity Plugin 2..3 and earlier versions. This vulnerability can increase the possibility of an attacker observing and capturing the user.pem key form field, leading to potential security risks.

In this long-read post, we will cover the details of CVE-2023-39155, provide code snippets to spot the vulnerability, explain the exploit, along with suggested remediations, and link to original references for further understanding.

What is Jenkins Chef Identity Plugin?
Jenkins Chef Identity Plugin (https://plugins.jenkins.io/chef-identity/) is a popular plugin used in the Jenkins automation server for managing Chef nodes, workspaces, and user identities. Jenkins (https://www.jenkins.io/) is an open-source automation server that allows developers to automate their software development processes, including build, test, and deployment.

Details of CVE-2023-39155

The main issue in Jenkins Chef Identity Plugin 2..3 and earlier versions is that the user.pem key form field is not masked. The user.pem file (a private key) is essential since it grants access to the Chef server. If an attacker can observe and capture the unmasked value, they can potentially gain unauthorized access to the Chef server. This could lead to unauthorized actions, such as modifying cookbooks, deploying rogue nodes, and more.

Code Snippet

To understand the vulnerability better, let's review a code snippet to illustrate the problem. The following example is written in Groovy, a scripting language used in Jenkins.

import jenkins.model.Jenkins

def chefPlugin = Jenkins.instance.getDescriptorByType(ChefIdentity.DescriptorImpl.class)
def chefGlobalConfig = chefPlugin.get()

println "User pem key: " + chefGlobalConfig.userPemKey

// The user.pem key form field:
// <input type="text" name="_.userPemKey" value="${it.userPemKey}"/>

In the example above, the user.pem key form field is displayed as a regular text input field without masking the value, increasing the risk of being observed and captured by attackers.

Exploiting CVE-2023-39155

Although no specific exploits have been reported for CVE-2023-39155, an attacker can leverage various means to capture the unmasked user.pem key form field. One such method is "shoulder surfing," where an attacker merely looks over the shoulder of a user while they are using the application. In a more sophisticated attack scenario, an attacker could use malware, such as keyloggers or screen recorders, to remotely capture the unmasked key from the user's system.

Suggested Remediations

To remediate the vulnerability of CVE-2023-39155, it is essential to upgrade to a more recent version of the Jenkins Chef Identity Plugin. The developers have released a fixed version (2..4) where the user.pem key form field is properly masked, reducing the risk of exposure. You can update to the latest version of the plugin from the Jenkins Plugin Manager or download it directly from https://updates.jenkins.io/download/plugins/chef-identity/.

It is also important to enforce strong security practices within your organization to safeguard sensitive information and monitor user activities.

1. Jenkins Security Advisory: https://www.jenkins.io/security/advisory/2023-02-21/#SECURITY-2484
2. CVE-2023-39155 Entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-39155
3. NVD CVE-2023-39155: https://nvd.nist.gov/vuln/detail/CVE-2023-39155

Conclusion

In conclusion, the CVE-2023-39155 vulnerability in the Jenkins Chef Identity Plugin 2..3 and earlier versions poses a security risk by not masking the user.pem key form field. It's vital to stay informed and update your application as soon as a new version is released to prevent potential security incidents. Moreover, implementing strong security policies and practices within your organization can help mitigate the chances of unauthorized access to sensitive information.

Timeline

Published on: 07/26/2023 14:15:00 UTC
Last modified on: 08/01/2023 20:33:00 UTC