CVE-2018-16868 Information disclosure in gnutls

Medium 4.7 Published 3 Dec 2018 Updated 5 Aug 2024

A local attacker can exploit a side-channel in GnuTLS to extract plaintext or downgrade TLS connections via a padding oracle attack.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2018-16868?

CVE-2018-16868 is a medium-severity vulnerability in Gnu Gnutls, published on 3 Dec 2018. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A Bleichenbacher type side-channel based padding oracle attack was found in the way gnutls handles verification of RSA decrypted PKCS#1 v1.5 data. An attacker who is able to run process on the same physical core as the victim process, could use this to extract plaintext or in some cases downgrade any TLS connections to a vulnerable server.

Weakness: CWE-203

Which versions are affected by CVE-2018-16868?

It affects 1 product.

Linux distribution packages (5)

`gnutls` SUSE:Linux Enterprise Module for Basesystem 15	All versions	`3.6.7-6.11.1`
`gnutls` SUSE:Linux Enterprise Module for Basesystem 15 SP1	All versions	`3.6.7-6.11.1`
`gnutls` SUSE:Linux Enterprise Module for Desktop Applications 15	All versions	`3.6.7-6.11.1`
`gnutls` openSUSE:Leap 15.0	All versions	`3.6.7-lp151.2.3.1`
`gnutls` openSUSE:Leap 15.1	All versions	`3.6.7-lp151.2.3.1`

Products include Gnu Gnutls.

How do I fix CVE-2018-16868?

Apply the vendor's patch.

Is CVE-2018-16868 being exploited?

There is no known exploitation of CVE-2018-16868 in the wild and no public exploit code.

All Gnu Gnutls vulnerabilities

Sources

Also known as DEBIAN-CVE-2018-16868, GHSA-qjx3-4wr5-3c93, MGASA-2019-0103, SUSE-SU-2019:1351-1, SUSE-SU-2019:1351-2, UBUNTU-CVE-2018-16868 and 1 more.