VDB-189848 · CVE-2021-35247 · GCVE-0-2021-35247

SolarWinds Serv-U Login Screen input validation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3	$0-$5k	0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in SolarWinds Serv-U. Affected is an unknown function of the component Login Screen. Such manipulation leads to input validation. This vulnerability is listed as CVE-2021-35247. The attack may be performed from remote. In addition, an exploit is available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in SolarWinds Serv-U (File Transfer Software) (affected version unknown). Affected by this issue is an unknown functionality of the component Login Screen. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The weakness was presented 01/10/2022. The advisory is shared for download at solarwinds.com. This vulnerability is handled as CVE-2021-35247 since 06/22/2021. Successful exploitation requires user interaction by the victim. Technical details are unknown but an exploit is available.

It is declared as attacked. This issue was added on 01/21/2022 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 02/04/2022:

Apply updates per vendor instructions.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

File Transfer Software

Vendor

SolarWinds

Name

Serv-U

License

commercial

Website

Vendor: https://www.solarwinds.com/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.3

VulDB Base Score: 6.3
VulDB Temp Score: 6.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.3
NVD Vector: 🔍

CNA Base Score: 4.3
CNA Vector (SolarWinds): 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Attacked

EPSS Score: 🔍
EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍
KEV Notice: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

06/22/2021 🔍
01/10/2022 +202 days 🔍
01/10/2022 +0 days 🔍
10/27/2025 +1386 days 🔍

Sourcesinfo

Vendor: solarwinds.com

Advisory: solarwinds.com
Status: Confirmed

CVE: CVE-2021-35247 (🔍)
GCVE (CVE): GCVE-0-2021-35247
GCVE (VulDB): GCVE-100-189848
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 01/10/2022 17:10
Updated: 10/27/2025 18:55
Changes: 01/10/2022 17:10 (47), 01/12/2022 08:40 (1), 04/22/2024 16:38 (26), 09/17/2024 17:21 (1), 02/14/2025 18:04 (17), 05/02/2025 07:19 (3), 10/27/2025 18:55 (1)
Complete: 🔍
Cache ID: 216::103