A Vulnerability in SolarWinds Serv-U Could Allow for Remote Code Execution

DESCRIPTION:
A vulnerability has been discovered in SolarWinds Serv-U, which could
result in remote code execution. SolarWinds Serv-U is an FTP server
software for secure file transfer. Successful exploitation of this
vulnerability could allow for remote code execution within the context
of a privileged process. Depending on the privileges associated with
this application, an attacker could then install programs; view, change,
or delete data; or create new accounts with full user rights. If this
application has been configured to have fewer user rights on the system,
exploitation of this vulnerability could have less impact than if it was
configured with administrative rights.

IMPACT:
A vulnerability has been discovered in SolarWinds Serv-U, which could
result in remote code execution. SolarWinds Serv-U is prone to a remote
memory escape vulnerability that could allow a threat actor to run
arbitrary code within the context of a privileged process. Depending on
the privileges associated with this application, an attacker could then
install programs; view, change, or delete data; or create new accounts
with full user rights. If this application has been configured to have
fewer user rights on the system, exploitation of this vulnerability
could have less impact than if it was configured with administrative rights.

SYSTEM AFFECTED:

* SolarWinds Serv-U versions prior to Serv-U 15.2.3 HF2

RECOMMENDATIONS:
We recommend the following actions be taken:

* Apply appropriate updates provided by SolarWinds to vulnerable systems
immediately after appropriate testing.
* Run all software as a non-privileged user (one without administrative
privileges) to diminish the effects of a successful attack.
* Remind users not to visit un-trusted websites or follow links provided
by unknown or un-trusted sources.
* Inform and educate users regarding the threats posed by hypertext
links contained in emails or attachments especially from un-trusted sources.
* Apply the Principle of Least Privilege to all systems and services.

REFERENCES:
https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211
https://www.bleepingcomputer.com/news/security/solarwinds-patches-critical-serv-u-vulnerability-exploited-in-the-wild/
https://www.zdnet.com/article/solarwinds-releases-security-advisory-after-microsoft-says-customer-targeted-through-vulnerability/
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-35211