Known Exploited Vulnerability
5.3
MEDIUM
CVE-2021-35247
SolarWinds Serv-U Improper Input Validation Vulner - [Actively Exploited]
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.

INFO

Published Date :

Jan. 10, 2022, 2:10 p.m.

Last Modified :

Nov. 21, 2024, 6:12 a.m.

Remotely Exploitable :

Yes !

Impact Score :

1.4

Exploitability Score :

3.9
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

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.

Required Action :

Apply updates per vendor instructions.

Notes :

https://nvd.nist.gov/vuln/detail/CVE-2021-35247

Public PoC/Exploit Available at Github

CVE-2021-35247 has a 3 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2021-35247 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Solarwinds serv-u
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-35247.

URL Resource
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://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

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

None

Updated: 4 weeks ago
0 stars 1 fork 1 watcher
Born at : April 4, 2023, 5:52 p.m. This repo has been linked 18 different CVEs too.

Ostorlab KEV: One-command to detect most remotely known exploitable vulnerabilities. Sourced from CISA KEV, Google's Tsunami, Ostorlab's Asteroid and Bug Bounty programs.

cisa-kev vulnerability 0day cisa exploits

Updated: 2 weeks, 2 days ago
548 stars 35 fork 35 watcher
Born at : April 19, 2022, 8:58 a.m. This repo has been linked 1228 different CVEs too.

Collection of resources for responding to the Log4j set of vulnerabilities.

Updated: 1 year, 2 months ago
10 stars 3 fork 3 watcher
Born at : Dec. 21, 2021, 3:51 a.m. This repo has been linked 7 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-35247 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-35247 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-3_release_notes.htm
    Added Reference https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35247
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Modified Analysis by [email protected]

    Feb. 10, 2022

    Action Type Old Value New Value
    Changed Reference Type https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-3_release_notes.htm No Types Assigned https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-3_release_notes.htm Release Notes, Vendor Advisory
    Changed CPE Configuration OR *cpe:2.3:a:solarwinds:serv-u:*:*:*:*:*:*:*:* versions up to (including) 15.2.5 OR *cpe:2.3:a:solarwinds:serv-u:*:*:*:*:*:*:*:* versions up to (excluding) 15.3
  • CVE Modified by [email protected]

    Jan. 25, 2022

    Action Type Old Value New Value
    Changed 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 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.
    Added Reference https://documentation.solarwinds.com/en/success_center/servu/content/release_notes/servu_15-3_release_notes.htm [No Types Assigned]
  • Modified Analysis by [email protected]

    Jan. 19, 2022

    Action Type Old Value New Value
    Removed CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:P)
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:P/A:N)
    Removed CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
    Changed Reference Type https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35247 Broken Link https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35247 Broken Link, Vendor Advisory
  • CVE Modified by [email protected]

    Jan. 18, 2022

    Action Type Old Value New Value
    Changed Description Serv-U web login screen was allowing characters that were not sanitized by the authentication mechanism. SolarWinds has updated the authentication mechanism to remedy this issue and prevent unauthorized parameters to be used in the Serv-U login screen With the Log4j issue in the wild, input fields across the internet have been tested for vulnerability. Although Serv-U was not affected by the log4j issue, It was discovered that better input validation could be implemented. 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
  • Initial Analysis by [email protected]

    Jan. 14, 2022

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:P)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35247 No Types Assigned https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35247 Broken Link
    Added CWE NIST CWE-20
    Added CPE Configuration OR *cpe:2.3:a:solarwinds:serv-u:*:*:*:*:*:*:*:* versions up to (including) 15.2.5
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-35247 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-35247 weaknesses.

CAPEC-3: Using Leading 'Ghost' Character Sequences to Bypass Input Filters Using Leading 'Ghost' Character Sequences to Bypass Input Filters CAPEC-7: Blind SQL Injection Blind SQL Injection CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-13: Subverting Environment Variable Values Subverting Environment Variable Values CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-22: Exploiting Trust in Client Exploiting Trust in Client CAPEC-23: File Content Injection File Content Injection CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-28: Fuzzing Fuzzing CAPEC-31: Accessing/Intercepting/Modifying HTTP Cookies Accessing/Intercepting/Modifying HTTP Cookies CAPEC-42: MIME Conversion MIME Conversion CAPEC-43: Exploiting Multiple Input Interpretation Layers Exploiting Multiple Input Interpretation Layers CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-52: Embedding NULL Bytes Embedding NULL Bytes CAPEC-53: Postfix, Null Terminate, and Backslash Postfix, Null Terminate, and Backslash CAPEC-63: Cross-Site Scripting (XSS) Cross-Site Scripting (XSS) CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic Using Slashes and URL Encoding Combined to Bypass Validation Logic CAPEC-67: String Format Overflow in syslog() String Format Overflow in syslog() CAPEC-71: Using Unicode Encoding to Bypass Validation Logic Using Unicode Encoding to Bypass Validation Logic CAPEC-72: URL Encoding URL Encoding CAPEC-73: User-Controlled Filename User-Controlled Filename CAPEC-78: Using Escaped Slashes in Alternate Encoding Using Escaped Slashes in Alternate Encoding CAPEC-79: Using Slashes in Alternate Encoding Using Slashes in Alternate Encoding CAPEC-80: Using UTF-8 Encoding to Bypass Validation Logic Using UTF-8 Encoding to Bypass Validation Logic CAPEC-81: Web Server Logs Tampering Web Server Logs Tampering CAPEC-83: XPath Injection XPath Injection CAPEC-85: AJAX Footprinting AJAX Footprinting CAPEC-88: OS Command Injection OS Command Injection CAPEC-101: Server Side Include (SSI) Injection Server Side Include (SSI) Injection CAPEC-104: Cross Zone Scripting Cross Zone Scripting CAPEC-108: Command Line Execution through SQL Injection Command Line Execution through SQL Injection CAPEC-109: Object Relational Mapping Injection Object Relational Mapping Injection CAPEC-110: SQL Injection through SOAP Parameter Tampering SQL Injection through SOAP Parameter Tampering CAPEC-120: Double Encoding Double Encoding CAPEC-135: Format String Injection Format String Injection CAPEC-136: LDAP Injection LDAP Injection CAPEC-153: Input Data Manipulation Input Data Manipulation CAPEC-182: Flash Injection Flash Injection CAPEC-209: XSS Using MIME Type Mismatch XSS Using MIME Type Mismatch CAPEC-230: Serialized Data with Nested Payloads Serialized Data with Nested Payloads CAPEC-231: Oversized Serialized Data Payloads Oversized Serialized Data Payloads CAPEC-250: XML Injection XML Injection CAPEC-261: Fuzzing for garnering other adjacent user/sensitive data Fuzzing for garnering other adjacent user/sensitive data CAPEC-267: Leverage Alternate Encoding Leverage Alternate Encoding CAPEC-473: Signature Spoof Signature Spoof CAPEC-588: DOM-Based XSS DOM-Based XSS CAPEC-664: Server Side Request Forgery Server Side Request Forgery
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.76 }} -0.05%

score

0.80926

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability