Internet-Exposed IBM BigFix Relays May Lead to Full Remote Compromise

March 21, 2019

Internet-facing relays in IBM BigFix deployments could lead to information disclosure and potential full remote compromise if not properly configured, Atredis Partners security researchers have discovered.

Tracked as CVE-2019-4061 and affecting BigFix Platform versions 9.5 - 9.5.11 and 9.2 - 9.2.16, the vulnerability is found in all deployments where relays that are exposed to the Internet are not configured as authenticating.

This misconfiguration could allow an unauthenticated, remote attacker to query the relay and gather information about the updates deployed to the associated sites.

"Internet-facing relays, if any, in a BigFix deployment might be configured as non-authenticating, which exposes the deployment to security risks," IBM notes in an advisory.

"Security attacks in this context might mean unauthorized access to the relays and any content or actions, and download packages associated with them or to the Relay Diagnostics page that might contain sensitive information (for example: software, vulnerability information, and passwords)," IBM continues.

According to Atredis Partners' security researchers, BigFix deployments with external relays that lack authentication expose a very large amount of information to unauthenticated external attackers, and could even lead to full remote compromise.

Some of the data an attacker could access includes server IP, server name, port numbers, digital signatures, and license information (details found in the masthead BigFix uses to publish info on installations), an index of configured sites, and a list of package names and versions.

The researchers also note that the BigFix data is still accessible to an attacker with access to the internal network or to an externally connected system with an authenticated agent, even if relay authentication is enabled.

"The best path to preventing a compromise through BigFix is to not include any sensitive content in uploaded packages," the researchers note.

An Internet-wide survey Atredis Partners conducted revealed the existence of 1,458 BigFix relay servers with relay authentication disabled. The researchers say they were able to query the masthead and obtain information on each of the discovered relays.

"This list included numerous government organizations, large multinational corporations, health care providers, universities, insurers, major retailers, and financial service providers, along with a healthy number of technology firms," the researchers reveal.

After being informed on the vulnerability, the BigFix team updated the documentation and took steps to notify affected customers, a process completed as of March 18, Atredis Partners says.

IBM recommends addressing the vulnerability by configuring Internet-facing relays in BigFix deployment as "authenticating". This would allow only BigFix clients in one's environment to connect to the relay and would also ensure that all communication will take place through TLS (HTTPS).

"This configuration also prevents any unauthorized access to the Relay Diagnostics page," IBM notes.

To enable the relays for authentication, one should head to the BES Support website and find the BES Client Settings: Enable Relay authentication fixlet. Next, they simply need to run the fixlet and wait for the action to finish.