CVE-2021-35211

Name: CVE-2021-35211
Creator: NVD / NIST
Published: 2021-07-14T21:15:08.09+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 10/10Actively ExploitedEPSS 91.16%

Last modified Jun 17, 2026

CVE-2021-35211 is a critical-severity vulnerability rated 10/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 91.16% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

10/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS Probability

91.16%

99.8th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Nov 17, 2021.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Solarwinds	Serv-U	< 15.2.3
Solarwinds	Serv-U	15.2.3

References

https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploitPatch, Vendor Advisory
https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211Patch, Vendor Advisory
https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploitPatch, Vendor Advisory
https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211Patch, Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35211US Government Resource

Timeline

Published: Jul 14, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-35211?

How severe is CVE-2021-35211?

CVE-2021-35211 has a CVSS score of 10/10 (CRITICAL severity). The EPSS model estimates a 91.16% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-35211?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-35211?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST