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Alert - Critical Vulnerabilities in Atlassian Confluence Servers

Number: AL19-007
Date: 29 April 2019

Audience

This Alert is intended for IT professionals and managers. Recipients of this information may redistribute it with no restrictions.

Purpose

An ALERT is used to raise awareness of a recently identified cyber threat Cyber threatA threat actor, using the internet, who takes advantage of a known vulnerability in a product for the purposes of exploiting a network and the information the network carries. that may impact cyber information assets, and to provide additional detection DetectionThe monitoring and analyzing of system events in order to identify unauthorized attempts to access system resources. and mitigation advice to recipients. The Canadian Centre for Cyber Security Cyber securityThe protection of digital information, as well as the integrity of the infrastructure housing and transmitting digital information. More specifically, cyber security includes the body of technologies, processes, practices and response and mitigation measures designed to protect networks, computers, programs and data from attack, damage or unauthorized access so as to ensure confidentiality, integrity and availability. ("Cyber Centre") is also available to provide additional assistance regarding the content of this ALERT to recipients as requested.

Assessment

The Cyber Centre is aware of the active exploitation of Atlassian Confluence Servers and Confluence Data Centers in recent weeks. Trusted researchers have identified targeted campaigns against Government Facilities Sectors that leverage multiple vulnerabilities.

The exploitations are believed to be leveraging the following known vulnerabilities:

CVE-2019-3395: A malicious actor is able to remotely exploit a Server-Side Request Forgery (SSRF) vulnerability VulnerabilityA flaw or weakness in the design or implementation of an information system or its environment that could be exploited to adversely affect an organization's assets or operations. in the WebDAV plugin to send arbitrary HTTP and WebDAV requests.

CVE-2019-3396: A server-side template injection vulnerability in the Widget Connector Macro allows a malicious actor to remotely execute arbitrary code.

CVE-2019-3398: A path traversal vulnerability in the “downloadallattachments” resource allows a malicious actor with specific permissions to remotely write files to arbitrary locations, which in turn could lead to remote code execution. An authenticated user would require one of the below permissions in order to execute this vulnerability:

  • Add attachments to pages and/or blogs
  • Create a new space or a personal space
  • ‘Admin’ privileges for a space

Suggested actions

The Cyber Centre recommends that Confluence Server and/or Data Center be patched to one of the below versions or higher:

  • 6.6.13
  • 6.12.4
  • 6.13.4
  • 6.14.3
  • 6.15.2

If it is not possible to patch an instance of Confluence Server, The Cyber Centre recommends that the additional mitigation steps provided by Atlassian, provided below, be taken as soon as possible.

References

Atlassian Security Advisory for CVE-2019-3395 and CVE -2019-3396: https://confluence.atlassian.com/doc/confluence-security-advisory-2019-03-20-966660264.html

Atlassian Security Advisory for CVE-2019-3398: https://confluence.atlassian.com/doc/confluence-security-advisory-2019-04-17-968660855.html

Note to readers

The Canadian Centre for Cyber Security (Cyber Centre) operates as part of the Communications Security Establishment. We are Canada's national authority on cyber security and we lead the government's response to cyber security events. As Canada's national computer security incident response team, the Cyber Centre works in close collaboration with government departments, critical infrastructure Critical infrastructureProcesses, systems, facilities, technologies, networks, assets, and services essential to the health, safety, security, or economic well-being of Canadians and the effective functioning of government. Critical infrastructure can be stand-alone or interconnected and interdependent within and across provinces, territories, and national borders. Disruptions of critical infrastructure could result in catastrophic loss of life, adverse economic effects, and significant harm to public confidence. , Canadian businesses and international partners to prepare for, respond to, mitigate, and recover from cyber events. We do this by providing authoritative advice and support, and coordinating information sharing and incident response. The Cyber Centre is outward-facing, welcoming partnerships that help build a stronger, more resilient cyber space in Canada.

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