CVE-2019-8460 Denial of service in OpenBSD

Q: Is CVE-2019-8460 being exploited?

There is no known exploitation of CVE-2019-8460 in the wild and no public exploit code.

Q: How do I fix CVE-2019-8460?

No fix has been published for CVE-2019-8460 yet. Limit exposure of the affected software until one is available.

High 7.5 Published 26 Aug 2019 Updated 4 Aug 2024

Attackers can cause a denial of service in OpenBSD by forcing the kernel to process expensive TCP SACK hole chains.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2019-8460?

CVE-2019-8460 is a high-severity denial of service vulnerability in Openbsd Openbsd, published on 26 Aug 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

OpenBSD kernel version <= 6.5 can be forced to create long chains of TCP SACK holes that causes very expensive calls to tcp_sack_option() for every incoming SACK packet which can lead to a denial of service.

Weakness: CWE-1049

Which versions are affected by CVE-2019-8460?

It affects 1 product.

Products include Openbsd Openbsd.

How do I fix CVE-2019-8460?

No fix has been published for CVE-2019-8460 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2019-8460 being exploited?

There is no known exploitation of CVE-2019-8460 in the wild and no public exploit code.

All Openbsd Openbsd vulnerabilities

Sources

Also known as GHSA-9q38-5hh6-p5gw.