CVE-2021-35247: SolarWinds Serv-U Improper Input Validation Vulnerability

Medium severity, CVSS 5.3. Actively exploited: in CISA KEV since 2022-01-21. EPSS: 3.5% chance of exploitation in the next 30 days.

Serv-U web login screen to LDAP authentication was allowing characters that were not sufficiently sanitized. SolarWinds has updated the input mechanism to perform additional validation and sanitization. Please Note: No downstream affect has been detected as the LDAP servers ignored improper characters. To insure proper input validation is completed in all environments. SolarWinds recommends scheduling an update to the latest version of Serv-U.

Affected products

• SolarWinds Serv-U: before 15.3 (fixed in 15.3)

Published 2022-01-10. Last modified 2026-06-17.