Critical RCE Vulnerability Reported in ConnectWise Server Backup Solution

IT service management software platform ConnectWise has released
Software patches for a critical security vulnerability in Recover
and R1Soft Server Backup Manager (SBM).

The issue, characterized^[1]
as a “neutralization of Special Elements in Output Used by a
Downstream Component,” could be abused to result in the execution
of remote code or disclosure of sensitive information.

ConnectWise’s advisory notes that the flaw affects Recover
v2.9.7 and earlier, as well as R1Soft SBM v6.16.3 and earlier, are
impacted by the critical flaw.

At its core, the issue is tied to an upstream authentication
bypass vulnerability in the ZK open source Ajax web application
framework (CVE-2022-36537^[2]), which was initially
patched in May 2022.

“Affected ConnectWise Recover SBMs have automatically been
updated to the latest version of Recover (v2.9.9),” the company
said^[3], urging customers to
upgrade to SBM v6.16.4^[4]
shipped on October 28, 2022.

Cybersecurity firm Huntress said^[5]
it identified “upwards of 5,000 exposed server manager backup
instances,” potentially exposing companies to supply chain
risks.

While there is no evidence of active exploitation of the
vulnerability in the wild, a proof-of-concept devised by Huntress
researchers John Hammond and Caleb Stewart shows that it can be
abused to bypass authentication, gain remote code execution on SBM,
and push LockBit 3.0 ransomware to all downstream endpoints.

“It is important to note that the upstream ZK vulnerability not
only affects R1Soft, but also any application utilizing an
unpatched version of the ZK framework,” the researchers said.

“The access an attacker can gain by using this authentication
bypass vulnerability is specific to the application being
exploited, however there is serious potential for other
applications to be affected in a similar way to R1Soft Server
Backup Manager.”