What’s Vulnerable › Vulnerabilities

CVE-2021-35211: SolarWinds Serv-U Remote Code Execution Vulnerability

• Severity: critical (CVSS 10.0 v3.1)
• Exploited in the wild: yes — in CISA KEV since 2021-11-03
• EPSS: 91.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-07-14 · updated 2026-06-17
• Weakness: CWE-787

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.

Affected products

• SolarWinds Serv-U: before 15.2.3; 15.2.3, 15.2.3-hotfix1 — fixed in 15.2.3

How to fix

Upgrade to a fixed version: SolarWinds Serv-U 15.2.3. Check the vendor advisory for mitigations.

References

• https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploit
• https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211
• https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploit
• https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35211

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