CVE-2021-35247

Name: CVE-2021-35247
Creator: NVD / NIST
Published: 2022-01-10T14:10:17.667+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10Actively ExploitedEPSS 3.36%

Last modified Jun 17, 2026

CVE-2021-35247 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 3.36% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS Probability

3.36%

87.2th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Feb 4, 2022.

Weakness Enumeration

CWE-20

Affected Software

Vendor	Product	Versions
Solarwinds	Serv-U	< 15.3

References

https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-3_release_notes.htmRelease Notes, Vendor Advisory
https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35247Broken Link, Vendor Advisory
https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-3_release_notes.htmRelease Notes, Vendor Advisory
https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35247Broken Link, Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35247US Government Resource

Timeline

Published: Jan 10, 2022
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-35247?

How severe is CVE-2021-35247?

CVE-2021-35247 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 3.36% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-35247?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-35247?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST