The Serv-U File Server allows for events such as user login failures to be audited by executing a command. This command can be supplied with parameters that can take the form of user string variables, allowing remote code execution.
Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability.
An issue was discovered in SolarWinds Serv-U before 15.2.2. Unauthenticated attackers can retrieve cleartext passwords via macro Injection. NOTE: this had a distinct fix relative to CVE-2020-35481.
In SolarWinds Serv-U before 15.2.2 Hotfix 1, there is a directory containing user profile files (that include users' password hashes) that is world readable and writable. An unprivileged Windows user (having access to the server's filesystem) can add an FTP user by copying a valid profile file to this directory. For example, if this profile sets up a user with a C:\ home directory, then the attacker obtains access to read or replace arbitrary files with LocalSystem privileges.