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Findings

CVE-2021-35247

SolarWinds Serv-U Improper Input Validation Vulnerability

Published Jan 10, 2022 · updated Jun 16, 2026 · solarwinds serv-u

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.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jan 10, 2022 · Catalog

    Detected

    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 schedu

  2. Jan 21, 2022 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. Feb 4, 2022 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Jun 16, 2026 · Catalog

    Updated

    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 schedu

Required action

Apply updates per vendor instructions.

CISA due date Feb 4, 2022

Affected

  • cpe solarwinds/serv-uversion unspecified
  • vendor SolarWinds Serv-Uversion unspecified

Sources

  • CISA KEVConfirmed exploitationCVE-2021-35247

    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.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2021-35247

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-35247

    30-day exploitation probability 3.5%

    first.org
  • NIST NVDVulnerability recordCVE-2021-35247

    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 ignor

    nvd.nist.gov

References