Linux Kernel dr_remove_all() Function Double-Free Arbitrary Code Execution Vulnerability [CVE-2019-3896]

CVE Number – CVE-2019-3896

A vulnerability in the Linux Kernel could allow a local attacker to escalate privileges on a targeted system.

The vulnerability exists in the dr_remove_all() function, as defined in the lib/idr.c source code file of the affected software, and is due to improper memory operations that are performed by the Linux Kernel. The vulnerability manifests as a double-free memory error condition. An attacker could exploit this vulnerability by accessing the system and executing an application that submits malicious input to the system. A successful exploit could allow the attacker to execute arbitrary code and completely compromise the system. 

Kernel.org has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, the attacker must have user-level access to the targeted system. This access requirement could reduce the likelihood of a successful exploit.

Safeguards

• Administrators are advised to apply the appropriate updates.
  
  Administrators are advised to allow only trusted users to access local systems.
  
  Administrators are advised to allow only privileged users to access administration or management systems.
  
  Administrators are advised to monitor critical systems.

Vendor Announcements

• Kernel.org has released changelogs at the following links: ChangeLog-3.2.40 and ChangeLog-3.4.87

Fixed Software

• Kernel.org has commited a source code update to the mainline kernel and released stable kernel updates at the following links: idr: fix top layer handling and The Linux Kernel Archives