CVE-2015-5283

What it actually does

Incorrect initialization order in the SCTP protocol setup routine allows a local process to trigger a kernel panic or memory corruption when SCTP sockets are instantiated before all required protocol structures are ready.

Why it matters to the business

Local users or compromised processes can crash affected systems, leading to unplanned downtime and potential data loss on servers or endpoints running vulnerable kernel versions; the issue has been publicly known for years with available exploits.

How an attack unfolds

An attacker with local access creates SCTP sockets immediately after module load or during early boot, racing the incomplete initialization sequence to trigger the panic or corruption before the kernel reaches a stable state.

How to fix it

Upgrade the Linux kernel to version 4.2.3 or later; apply the stable backports provided by your distribution for the running kernel series; disable SCTP via modprobe blacklist if the protocol is not required.

How to confirm the fix worked

Confirm the running kernel version is 4.2.3 or newer; attempt to reproduce the race condition in a controlled test environment and verify no panic occurs; review kernel changelog entries for the SCTP initialization fix.

Typical attack path

1. Obtain local shell or code execution on target system
2. Load or trigger SCTP protocol if not already active
3. Rapidly create multiple SCTP sockets before full initialization completes
4. Trigger kernel panic or memory corruption resulting in denial of service

How to detect it

Search system logs for kernel panics or oops messages referencing sctp_init or protocol.c around the time of unexpected reboots; look for processes that rapidly create SCTP sockets shortly after boot or module load.

What your security team should do

• Prioritize kernel upgrades on all systems exposing SCTP or reachable by untrusted local users
• Restrict local user accounts and container workloads that could create SCTP sockets
• Monitor for kernel oops or panic logs related to SCTP initialization
• Blacklist the SCTP module on systems where it is unnecessary