CVE-2019-14850: Low severity nbdkit vulnerability
A denial of service vulnerability was discovered in nbdkit 1.12.7, 1.14.1 and 1.15.1. An attacker could connect to the nbdkit service and cause it to perform a large amount of work in initializing backend plugins, by simply opening a connection to the service. This vulnerability could cause resource consumption and degradation of service in nbdkit, depending on the plugins configured on the server-side.
Other sources
An attacker, by connecting to nbdkit’s TCP port, is able to make the current plugin’s .open() callback run. For some plugins this callback does a considerable amount of work, for example connecting to a remote machine (nbdkit-ssh-plugin) or launching a small VM (nbdkit-guestfs-plugin). Thus for a small amount of work done by the attacker (opening many TCP connections but not sending any data), a large amount of work is done by nbdkit (eg. making many full ssh connections to a remote machine or launching hundreds of VMs).
A related problem is that if nbdkit is configured to use TLS for client authentication, even clients which are not authorized are able to attack nbdkit in this way because all they have to do is open a TCP connection.
Mitigating this is that the current plugin is NOT selected by the attacker, but is part of the server configuration. Therefore the effectiveness of the attack depends on the particular configuration.
— Red Hat
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is CVE-2019-14850?
CVE-2019-14850 is a denial of service vulnerability in nbdkit 1.12.7, 1.14.1, and 1.15.1.
How does CVE-2019-14850 work?
CVE-2019-14850 allows an attacker to perform a large amount of work in initializing backend plugins by simply opening a connection to the nbdkit service.
What is the severity of CVE-2019-14850?
The severity of CVE-2019-14850 is low with a CVSS score of 3.7.
Which software versions are affected by CVE-2019-14850?
The affected software versions are nbdkit 1.12.7, 1.14.1, and 1.15.1.
How can I fix CVE-2019-14850?
To fix CVE-2019-14850, update nbdkit to versions 1.12.8, 1.14.2, or 1.15.2.