CVEs / CVE-2021-35247
CVE-2021-35247: SolarWinds Serv-U Improper Input Validation Vulnerability
- Known exploited in the CISA KEV catalog since 21 Jan 2022
- medium 5.3 CVSS 3.1 (NVD)
- EPSS 3.45% chance of exploitation in the next 30 days, higher than 89% of CVEs (30 Oct 2026)
- Last changed at its sources
Are you affected? Check your servers with Stackurity: it lists the software on each server and the vulnerabilities to fix first.
Check your servers with Stackurity Already using Stackurity? Search for CVE-2021-35247
Summary
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.
Description
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 and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| SolarWinds Serv-U | from 15.2.5 and previous versions, before 15.3 | 15.3 |
Exploitation
| In CISA KEV since | 21 Jan 2022 |
|---|---|
| Due date for US federal agencies | 4 Feb 2022 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 5.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NScored by NVD |
|---|---|
| Weakness | CWE-20 |
References
- CVE-2021-35247 on NVD
- CVE-2021-35247 in the CISA KEV catalog
- https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-3_release_notes.htm Release Notes, Vendor Advisory
- https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35247 Broken Link, Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35247 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.