CVE-2022-1015

What it actually does

Out-of-bounds write in nf_tables_api.c of the netfilter subsystem permits a local process to corrupt adjacent kernel memory structures.

Why it matters to the business

Linux systems face elevated risk of local privilege escalation or denial-of-service, potentially disrupting servers, containers, and endpoints until kernels are updated; widespread use in distributions increases exposure across many environments.

How an attack unfolds

An attacker with a local account crafts malicious nftables rules that trigger the out-of-bounds write during rule processing, allowing memory corruption that can be leveraged for code execution or crash; public exploit code exists and the flaw has been known since 2022.

How to fix it

Upgrade the Linux kernel to a version containing the fix for this memory corruption issue; apply distribution security updates promptly and rebuild any custom kernels with the patch.

How to confirm the fix worked

Verify running kernel version against fixed releases from the distribution; inspect nftables configuration for unexpected rules and test rule loading in a non-production environment.

Typical attack path

1. Gain local shell or user account on target Linux system
2. Load or modify nftables configuration to exercise the vulnerable nf_tables_api path
3. Trigger out-of-bounds write to corrupt kernel memory
4. Escalate privileges or cause denial of service

How to detect it

Review system logs for unusual nftables or netfilter errors around rule processing; examine process activity involving nft or iptables commands from non-administrative users.

What your security team should do

• Apply kernel updates immediately on all affected systems
• Restrict local user access and nftables privileges where possible
• Monitor for new public exploits and update detection rules accordingly