CVE-2023-45871

What it actually does

Inadequate buffer allocation in the IGB network driver allows frames exceeding the configured MTU to overflow internal structures when processed on adjacent network links.

Why it matters to the business

Linux systems using Intel IGB Ethernet adapters face elevated risk of remote code execution or denial of service from attackers on the same network segment, potentially disrupting operations and requiring urgent kernel updates across server fleets.

How an attack unfolds

An attacker positioned on the local network segment crafts and transmits oversized Ethernet frames targeting the vulnerable IGB driver; the kernel processes the frames without sufficient bounds checking, resulting in memory corruption that can be leveraged for code execution or system instability.

How to fix it

Upgrade the Linux kernel to a version containing commit 238589d0f7b421aae18c5704dc931595019fa6c7 or later (equivalent to 6.5.3 or newer); rebuild and deploy the updated kernel across affected systems; where immediate patching is not feasible, isolate IGB interfaces or apply driver-level workarounds if available.

How to confirm the fix worked

Verify the running kernel version is 6.5.3 or newer; inspect the igb_main.c source for the presence of the referenced commit; test network interface behavior with oversized frames under controlled conditions to confirm bounds enforcement.

Typical attack path

1. Gain access to the same Layer 2 network as the target host
2. Identify hosts using the vulnerable IGB driver via network reconnaissance
3. Transmit crafted frames larger than the MTU to trigger the buffer condition
4. Exploit resulting memory corruption for privilege escalation or denial of service

How to detect it

Review kernel logs for IGB driver crashes or warnings related to frame processing; correlate network traffic captures showing MTU-exceeding frames with subsequent system instability events; examine audit logs for unexpected process behavior following network activity on IGB interfaces.

What your security team should do

• Prioritize kernel upgrades on all systems exposing IGB interfaces to untrusted adjacent networks
• Monitor EPSS trend and reassess exploit maturity as new information emerges
• Apply network segmentation to limit exposure of affected hosts
• Schedule validation scans post-remediation to confirm patch deployment