CVE-2017-7521 Denial of service in OpenVPN

Medium 5.9 Published Updated

Remote attackers can cause denial of service in OpenVPN servers via memory exhaustion from leaks and double-free errors in certificate processing.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2017-7521?

CVE-2017-7521 is a medium-severity denial of service vulnerability in OpenVPN, published on 27 Jun 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to remote denial-of-service due to memory exhaustion caused by memory leaks and double-free issue in extract_x509_extension().

Weakness: CWE-772, CWE-415, CWE-400

Which versions are affected by CVE-2017-7521?

It affects 1 product.

Products include Openvpn Openvpn.

How do I fix CVE-2017-7521?

Upgrade to a fixed version.

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-2017-7521 being exploited?

There is no known exploitation of CVE-2017-7521 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2017-7521, GHSA-mmxr-6344-9fv5, UBUNTU-CVE-2017-7521.

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