CVE-2013-6424

What it actually does

Integer underflow in the xTrapezoidValid macro allows a negative bottom value to trigger memory corruption resulting in a crash.

Why it matters to the business

Attackers can remotely crash affected services causing denial of service and operational disruption; the vulnerability is more than a decade old with no known active exploitation campaigns.

How an attack unfolds

An attacker supplies a specially crafted input containing a negative bottom value to the vulnerable macro, triggering an integer underflow that corrupts memory structures and forces the process to terminate.

How to fix it

Upgrade ingress-nginx-controller-fips-1.9 and kube-webhook-certgen-fips-1.9 to version 1.9.6-r6 or later; rebuild and redeploy all dependent container images after patching.

How to confirm the fix worked

Confirm running container images report version 1.9.6-r6 or newer via image metadata inspection or package manager queries; retest affected render functions with negative bottom values to verify absence of crash.

Typical attack path

1. Identify a network-accessible service using the affected X.Org render code path
2. Craft a request or data structure embedding a negative trapezoid bottom value
3. Send the malformed input to trigger the xTrapezoidValid macro
4. Observe service crash and loss of availability

How to detect it

Review application and system logs for unexpected process terminations or segmentation faults around the time of suspected attacks; no specific post-exploitation artifacts are known for this issue.

What your security team should do

• Immediately update all instances of the listed packages to the fixed versions
• Scan container registries and CI pipelines for any remaining vulnerable image tags
• Monitor EPSS and KEV feeds for any future change in exploitability