CVE-2025-38057

What it actually does

Missing kfree_skb calls on error paths in espintcp allow socket buffers to leak, leading to gradual kernel memory exhaustion.

Why it matters to the business

Systems may experience degraded performance or denial of service under sustained load; widespread kernel deployments increase exposure across servers and devices.

How an attack unfolds

A local attacker triggers error paths in espintcp processing to repeatedly leak skbs; over time memory pressure builds, potentially enabling further attacks. Listed threat actors associated with similar Linux kernel issues suggest possible chaining in advanced campaigns.

How to fix it

Update the Linux kernel to a version containing commit 05db2b850a2b8b17f3d1799f563ea1d550e05ed5 or later; apply vendor backports where available.

How to confirm the fix worked

Confirm the running kernel includes the referenced commit or equivalent fix; review changelog entries for espintcp skb handling.

Typical attack path

1. Obtain local user access on a vulnerable Linux system
2. Trigger network or socket operations that exercise espintcp error paths
3. Repeat to accumulate leaked socket buffers
4. Monitor for memory exhaustion or combine with other techniques for impact

How to detect it

Review kernel logs for repeated espintcp errors coinciding with unexplained memory growth; correlate with process activity that exercises IPsec TCP encapsulation.

What your security team should do

• Prioritize kernel updates on internet-facing and high-value systems within standard patch windows
• Monitor memory usage trends on systems using espintcp
• Review downstream package maintainers for coordinated updates