Date: October 17, 2018
Affected Versions: All previous Nexus Repository Manager 3 OSS/Pro versions up to and including 3.13.0
Fixed in Version: Nexus Repository Manager OSS/Pro version 3.14.0
Risk: Medium - 6.1 (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)
Summary:
Multiple Cross-Site Scripting (XSS) vulnerabilities have been discovered in Nexus Repository Manager 3.
A remote attacker can execute arbitrary JavaScript within the context of the Nexus application. We have mitigated the issue through instructions provided by the upstream library authors, and they have fixed the vulnerability in their library. This advisory provides the pertinent information needed to properly address this vulnerability, along with the details on how to reach us if you have any further questions or concerns.
These vulnerabilities were identified by external researchers and internal employees and have been verified by our security team. We 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 allows arbitrary JavaScript to run in a Nexus user’s browser in the context of the Nexus application. In regards to XSS, it is common that the injected JavaScript could forge requests on behalf of the user, redirect the user to another site, modify the page content or hijack their session. However, hijacking of a user’s session is not possible in Nexus as the session cookie is marked as HttpOnly. We are highly recommending all instances of Nexus be upgraded to Nexus 3.14 or later.
Publicly available Nexus Repository Manager instances are at greater risk and we have taken steps to mitigate this vulnerability in known public forge instances as well as providing remediation guidance to the overall Nexus Repository Manager user community.
The vulnerability associated with this advisory is fixed in Nexus 3.14 and above.
For detailed information on upgrade compatibility, please see:
https://support.sonatype.com/hc/en-us/articles/115000350007
Credit:
Sonatype thanks Dominik Schneider and Till Osswald, ERNW GmbH for responsibly reporting the identified issues and working with us as we addressed them.
Support:
If you run into any problems, or have any questions/concerns, please contact us by filing a ticket at https://support.sonatype.com.
Frequently Asked Questions:
Q: What is the risk associated with this vulnerability?
A: An attacker can execute arbitrary JavaScript within the context of the Nexus application leading to the compromise of the confidentiality and integrity of data.
Q: What preconditions must be met in order to be vulnerable?
A: In most cases, an attacker must have network access to the Repository Manager instance. However, there is one instance where an unauthenticated remote attacker can exploit the vulnerability.
Q: Are there implications associated with this advisory itself?
A: Disclosure unfortunately means bad actors may try to take advantage. While we have initially limited the information to the minimum details necessary for users to affect an appropriate fix, this merely slows down a would be attacker. As such, we are advising all organizations utilizing Nexus Repository Manager to immediately assess their individual impact and take appropriate action in response.
Q: Where can I obtain more information associated with the vulnerability?
A: At this time, and in the interest of best protecting our user community, we are limiting the information released to that absolutely required in order to assess impact and affect remediation. Please contact support for more information.
Q: Why is Sonatype making this information available?
A: This is part of a responsible disclosure process. Given Nexus Repository Manager is an open source project with over 150,000 active server installations, notifying the user base will invariably lead to broad dissemination. We are taking a concerted and proactive approach in our outreach activities and an effort to achieve the most rapid remediation possible.