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CVE-2021-35247 SolarWinds CVE debrief

CVE-2021-35247 is a SolarWinds Serv-U improper input validation vulnerability that was added to CISA’s Known Exploited Vulnerabilities (KEV) catalog on 2022-01-21. The KEV listing means CISA considered it actively exploited and set a remediation due date of 2022-02-04. The supplied corpus does not include a CVSS score, so defensive prioritization should be driven by the KEV status and vendor guidance rather than severity scoring alone.

Vendor
SolarWinds
Product
Serv-U
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2022-01-21
Original CVE updated
2022-01-21
Advisory published
2022-01-21
Advisory updated
2022-01-21

Who should care

Organizations that use SolarWinds Serv-U, along with security operations, vulnerability management, and patch management teams responsible for remediating KEV-listed vulnerabilities.

Technical summary

The available source material identifies the issue as an improper input validation vulnerability in SolarWinds Serv-U. Beyond that classification, the supplied corpus does not provide exploit mechanics, affected versions, or impact details. The key defensive signal is CISA’s KEV inclusion, which indicates known exploitation and a need for prioritized remediation.

Defensive priority

High. CISA listed this CVE in the KEV catalog on the same date shown in the supplied timeline, with a remediation due date of 2022-02-04. KEV-listed vulnerabilities should be treated as urgent patching priorities.

Recommended defensive actions

  • Inventory all SolarWinds Serv-U deployments and determine which instances are exposed or still in service.
  • Apply SolarWinds updates per vendor instructions as soon as possible.
  • Track remediation against the CISA KEV due date context and confirm closure in vulnerability management records.
  • Review the official vendor and CISA references for any version-specific remediation guidance.
  • Validate that patched systems are current and that any residual Serv-U instances are documented for follow-up.

Evidence notes

Source corpus identifies the vulnerability as SolarWinds Serv-U improper input validation. CISA’s KEV metadata lists vendorProject SolarWinds, product Serv-U, dateAdded 2022-01-21, dueDate 2022-02-04, and requiredAction: 'Apply updates per vendor instructions.' The supplied corpus does not provide a CVSS score or additional technical impact details. Official links provided: CVE.org record, NVD detail, CISA KEV catalog, and the CISA source JSON.

Official resources

Publicly disclosed as a CISA KEV-listed vulnerability on 2022-01-21. The supplied corpus indicates known exploitation status, but does not include further exploitation details or a CVSS score.