CVE-2016-6309 Use after free in n/a

Critical 9.8 Published 26 Sep 2016 Updated 6 Aug 2024

Remote attackers can cause denial of service or execute arbitrary code via crafted TLS sessions due to a use-after-free flaw in OpenSSL.

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

What is CVE-2016-6309?

CVE-2016-6309 is a critical use after free vulnerability in Openssl Openssl, published on 26 Sep 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

statem/statem.c in OpenSSL 1.1.0a does not consider memory-block movement after a realloc call, which allows remote attackers to cause a denial of service (use-after-free) or possibly execute arbitrary code via a crafted TLS session.

Weakness: CWE-416

Which versions are affected by CVE-2016-6309?

It affects 1 product.

Products include Openssl Openssl.

How do I fix CVE-2016-6309?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2016-6309 being exploited?

There is no known exploitation of CVE-2016-6309 in the wild and no public exploit code.

All Openssl Openssl vulnerabilities

Sources

Also known as GHSA-5qvw-r534-xcm4.