Kubernetes kubectl Directory Traversal Vulnerability [CVE-2019-1002101]

CVE Number – CVE-2019-1002101

A vulnerability in the kubectl cp command of Kubernetes could allow a local attacker to conduct a directory traversal attack on a targeted system.

The vulnerability is due to improper validation and sanitization of user-supplied input by the affected software when processing tar files. An attacker able to stage a malicious tar file in a container could exploit the vulnerability by persuading a user to use the kubectl cp command to copy the file to the user’s system. A successful exploit could allow the attacker to overwrite or delete arbitrary files in the security context of the user.Kubernetes has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, the attacker may use misleading language or instructions to persuade a user to access a file that submits malicious input to the affected software.

Safeguards

• Administrators are advised to apply the appropriate updates.
  
  Administrators are advised to allow only trusted users to have network access.
  
  Administrators are advised to use an unprivileged account when browsing the Internet.
  
  Administrators are advised to monitor critical systems.
  
  Users are advised not to open email messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in email messages are safe, they are advised not to open them.
  
  Users are advised not to visit websites or follow links that have suspicious characteristics or cannot be verified as safe.

Vendor Announcements

• Kubernetes has published a github pull request at the following link: CVE-2019-1002101: kubectl fix potential directory traversal #75037

Fixed Software

• Kubernetes has released software updates at the following link: Kubernetes Releases