CVE-2014-0240

What it actually does

The flaw allows a local user to escalate privileges by exploiting improper handling of setuid error codes returned when daemon mode is active on affected Linux kernels; success depends on the current count of running processes.

Why it matters to the business

A local attacker can obtain root-level access on systems running vulnerable versions, enabling full control of the web server and any data or services it hosts; because the issue is more than a decade old and has seen negligible exploitation, the risk is mainly to legacy or unpatched deployments.

How an attack unfolds

An attacker with a local shell account on a host using mod_wsgi in daemon mode crafts a scenario where setuid fails due to the kernel's process-count behavior, resulting in the worker process retaining elevated privileges that can then be used to compromise the system.

How to fix it

Upgrade mod_wsgi to version 3.5 or later and restart Apache; if the package cannot be updated, disable daemon mode or isolate the affected hosts until migration is possible.

How to confirm the fix worked

Verify the installed mod_wsgi version is 3.5 or newer; review Apache configuration to confirm daemon mode is either disabled or the updated module is loaded.

Typical attack path

1. Obtain a local user account on the target host
2. Confirm mod_wsgi is running in daemon mode
3. Manipulate the number of processes to trigger the setuid error-handling flaw
4. Execute code in the context of the privileged worker process

How to detect it

Search system and Apache logs for unexpected privilege changes or worker-process anomalies around the time of process-count spikes; review authentication and sudo logs for local users attempting escalation.

What your security team should do

• Identify all hosts still running mod_wsgi before version 3.5
• Schedule immediate upgrade or decommissioning of legacy instances
• Harden local access controls and monitor for unusual process behavior on remaining systems