SolarWinds · Serv-U
CVE-2021-35247
Improper Input Validation Vulnerability in Serv-U
What it is
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.
CISA: SolarWinds Serv-U versions 15.2.5 and earlier contain an improper input validation vulnerability that allows attackers to build and send queries without sanitization.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: February 4, 2022
More exploited flaws from SolarWinds
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Jun 5, 2026 | Uncontrolled Resource Consumption | Serv-U | High 7.5 | 44% |
| Jul 17, 2024 | Path Traversal Vulnerability | Serv-U | High 8.6 | 99.6% |
| Nov 3, 2021 | Remote Code Execution | Serv-U | Critical 9.0 | 91% |
| Mar 9, 2026 | Deserialization of Untrusted Data | Web Help Desk | Critical 9.8 | 90% |
| Feb 12, 2026 | Security Control Bypass | Web Help Desk | High 8.1 | 74% |
| Feb 3, 2026 | Deserialization of Untrusted Data | Web Help Desk | Critical 9.8 | 84% |
| Oct 15, 2024 | Hardcoded Credential | Web Help Desk | Critical 9.1 | 93% |
| Aug 15, 2024 | Deserialization of Untrusted Data | Web Help Desk | Critical 9.8 | 85% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.