Sonatype Nexus Security Advisory
Date: January 14, 2014
Affected Versions: Nexus OSS/Pro versions prior to and including 2.7.0-06
A critical security vulnerability has been discovered by Sonatype in Nexus requiring immediate action. The vulnerability makes use of an execution path in an open source library that we have now (with the available patch) added a mitigating control for. This advisory provides the pertinent information needed to properly mitigate this vulnerability, along with the details on how to reach us if you have any further questions or concerns.
We identified this vulnerability during our security research activities and are not aware of any active exploits taking advantage of this issue. However, we strongly encourage all users of Nexus to immediately take the steps outlined in this advisory.
The identified vulnerability can allow an attacker controlled remote object creation and arbitrary code execution in the running Nexus instance without requiring user authentication. Although not every version of Nexus has been proven to allow for arbitrary code execution and object creation we are still considering the possibility that such a condition may exist, and we are highly recommending all instances of Nexus have the patch, detailed in this advisory, applied.
We are taking steps to mitigate this vulnerability in public forge instances and are also providing remediation guidance to the overall Nexus user community. We are currently coordinating with NIST as part of the vulnerability disclosure process and further details will become publicly available as soon as that process is complete. The placeholder identifier for this vulnerability is CVE-2014-0792.
The vulnerability is fixed in Nexus 2.7.1, which can be downloaded from the links below:
If you want to patch an existing instance to address this vulnerability see below.
Compatibility of Patch:
This patch can be installed on any Nexus 2.x version. If you are running a 1.x version of Nexus you must upgrade before applying this patch. For detailed information on upgrade compatibility, please see:
The latest versions of Nexus can be found here:
Archived 2.x releases can be found here:
This patch works by building a white-list of allowed classes which can be instantiated. This mechanism will cover all Nexus use cases, but it may not cover all third party (non-Sonatype) Nexus plugins. We advise testing the patch in a non-production instance if you are using third party plugins.
If there is an issue related to the patch it will manifest itself in response to HTTP requests failing with error 400. In the logs you will see a message such as the following:
WARN: ...whitelist.TypeWhitelist - Type NOT allowed: <classname>
ConversionException: No converter specified for class <classname>
If you encounter this error see the Configuration section below for instructions on how to remedy the problem.
After successful installation you will see a message like this in the $NEXUS_HOME/logs/wrapper.log file:
2014-01-07 14:43:47 INFO [jetty-main-thread-1] -
Note: The message is logged too early to be seen in the nexus.log file
If you are using plugins which are not supplied by Sonatype that register with xstream in a non-standard way it may be necessary to extend the whitelist. Please see the configuration article for instructions.
Frequently Asked Questions:
Q: What is the risk associated with this vulnerability?
Q: What preconditions must be met in order to be vulnerable?
Q: Are there implications associated with this advisory itself?
Q: Where can I obtain more information associated with the vulnerability?
Q: How did Sonatype discover this vulnerability?
Q: Was Sonatype’s CLM platform used in response to this vulnerability?
|Free forum by Nabble||Edit this page|