CVE-2014-3673

What it actually does

Remote malformed ASCONF chunk in SCTP processing triggers a kernel crash due to insufficient input validation in net/sctp/sm_make_chunk.c and net/sctp/sm_statefuns.c.

Why it matters to the business

Attackers can remotely crash affected Linux systems, causing unplanned outages and service disruption across servers and network appliances that rely on SCTP.

How an attack unfolds

An attacker sends a single crafted SCTP packet containing a malformed ASCONF chunk to a system listening on an SCTP-enabled port; the kernel's state machine fails to handle the chunk safely and triggers a panic.

How to fix it

Upgrade the Linux kernel to a version containing the fix for this issue (post-3.17.2 patches in stable branches) and reboot affected systems. Apply vendor security updates for all listed distributions.

How to confirm the fix worked

Verify the running kernel version is newer than 3.17.2 and contains the SCTP ASCONF handling corrections; confirm no crash occurs when replaying the malformed chunk in a test environment.

Typical attack path

1. Scan for hosts exposing SCTP ports
2. Craft and transmit a single malformed ASCONF chunk
3. Trigger kernel panic and system crash on the target

How to detect it

Review system and kernel logs for SCTP-related panics or oops entries around the time of suspected incidents; inspect network captures for unexpected ASCONF chunks on SCTP flows.

• kernel: Unable to handle kernel NULL pointer dereference
• sctp: Invalid ASCONF chunk
• kernel panic - not syncing: Fatal exception

What your security team should do

• Prioritize kernel updates on all internet-facing or SCTP-enabled systems
• Disable SCTP where not required
• Monitor for kernel oops or panic logs containing SCTP references