CVE-2024-50168

What it actually does

The sun3_82586_send_packet() function returns NETDEV_TX_OK without calling dev_kfree_skb() when skb->len is too long, causing a potential memory leak in the obsolete Sun3 82586 network driver.

Why it matters to the business

On the rare systems still using this ancient driver, repeated triggering could slowly exhaust memory and degrade availability, though the low EPSS, lack of KEV listing, and obsolete hardware limit real-world operational risk even after 704 days.

How an attack unfolds

An attacker sends network frames with excessive skb length to the sun3_82586 interface; each un-freed skb accumulates until memory pressure leads to denial of service. No named threat actors are associated with this specific leak.

How to fix it

Apply the upstream fix adding dev_kfree_skb() or upgrade affected packages; on Ubuntu 14.04 LTS use firefox 43.0+build1-0ubuntu0.14.04.1 and thunderbird 1:38.5.1+build2-0ubuntu0.14.04.1 (or later).

How to confirm the fix worked

Inspect the sun3_82586.c source for the dev_kfree_skb() call after the length check, rebuild the driver, and confirm no skb leak under crafted long-packet test traffic.

Typical attack path

1. Locate a system exposing the sun3_82586 driver
2. Craft and transmit packets exceeding the length check
3. Repeat transmission to accumulate unfreed skbs
4. Observe memory exhaustion and service degradation

How to detect it

Review kernel logs and memory statistics on systems with the sun3_82586 driver for repeated allocation without corresponding frees; correlate with inbound traffic patterns matching the length condition.

What your security team should do

• Prioritize patching any remaining Ubuntu 14.04 systems running the listed firefox or thunderbird versions
• Remove or disable the sun3_82586 driver on modern kernels where possible
• Monitor memory usage on legacy Sun3 hardware for anomalous growth