CVE-2021-35223

Execute Command Function Allows Remote Code Execution (RCE)Vulnerability

8.5 High

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

2.94%Up 1.1 points since Sep 1, 2021

What each source reports

CVE List Score used 8.5

Execute Command Function Allows Remote Code Execution (RCE)Vulnerability

Record: CVE-2021-35223
CVSS 3.1: 8.5 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness: CWE-20
Updated: 2026-11-02

EUVDEUVD-2021-21866 8.5

Record: EUVD-2021-21866
CVSS 3.1: 8.5 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Updated: 2026-11-03

GitHub AdvisoriesGHSA-7822-xr7f-c5pr No score

The Serv-U File Server allows for events such as user login failures to be audited by executing a...

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.

Record: GHSA-7822-xr7f-c5pr
Updated: 2026-11-02

NVD 8.5

Record: CVE-2021-35223
CVSS 3.1: 8.5 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 6.5 MediumAV:N/AC:L/Au:S/C:P/I:P/A:P
Weakness: CWE-20
Updated: 2026-11-02

Affected products

solarwinds serv-u

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-35223 is a high vulnerability (CVSS 8.5) in Solarwinds Serv-u, published August 31, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.94%, the 87th percentile. No source names a fixed version.