Critical SolarWinds RCE Bugs Enable Unauthorized Network Takeover

Eight newly discovered vulnerabilities in the SolarWinds Access Rights Manager Tool (ARM) — including three deemed to be of critical severity — could open the door for attackers to gain the highest levels of privilege in any unpatched systems.

As a broad IT management platform, SolarWinds occupies a uniquely sensitive place in corporate networks, as the world learned the hard way three years ago. Its power to oversee and affect critical components in a corporate network is nowhere better epitomized than in its ARM tool, which administrators use to provision, manage, and audit user access rights to data, files, and systems.

So, admins should take note that on Thursday, Trend Micro's Zero Day Initiative (ZDI) revealed a series of "High" and "Critical"-rated vulnerabilities in ARM. As Dustin Childs, head of threat awareness at the ZDI, explains, "The most severe of these bugs would allow a remote unauthenticated attacker to execute arbitrary code at system level. They could completely take over an affected system. While we did not look at exploitability, the potential of these vulnerabilities is about as bad as it gets."

Serious Issues in SolarWinds ARM

Two of the eight vulnerabilities — CVE-2023-35181 and CVE-2023-35183 — allow unauthorized users to abuse local resources and incorrect folder permissions to perform local privilege escalation. Each was assigned a "High" severity rating of 7.8 out of 10.

A few more — CVE-2023-35180, CVE-2023-35184, and CVE-2023-35186, all rated 8.8 out of 10 by Trend Micro — open the door for users to abuse a SolarWinds service, or its ARM API, in order to perform remote code execution (RCE).

The most concerning of the bunch, however, are another trio of RCE vulnerabilities that Trend Micro assigned "critical" 9.8 ratings: CVE-2023-35182, CVE-2023-35185, and CVE-2023-35187. (For its part, SolarWinds diverged from Trend Micro here, assigning them all 8.8 ratings.)

In each case, a lack of proper validation for the methods createGlobalServerChannelInternal, OpenFile, and OpenClientUpdateFile, respectively, could enable attackers to run arbitrary code at the SYSTEM level — the highest possible level of privilege on a Windows machine. And unlike the other five bugs released Thursday, these three do not require prior authentication for exploitation.

A new ARM version 2023.2.1, pushed to the public on Wednesday, fixes all eight vulnerabilities. SolarWinds clients are advised to patch immediately.