VDB-330722 · CVE-2021-47690 · GCVE-0-2021-47690

Nagios XI up to 5.8.1 Overlay Modals cross site scripting

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.
4.4	$0-$5k	0.00

Summaryinfo

A vulnerability classified as problematic was found in Nagios XI up to 5.8.1. The impacted element is an unknown function of the component Overlay Modals. Such manipulation leads to cross site scripting. This vulnerability is uniquely identified as CVE-2021-47690. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Nagios XI up to 5.8.1. It has been rated as problematic. Affected by this issue is an unknown function of the component Overlay Modals. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. CVE summarizes:

The Core Config Manager (CCM) in Nagios XI versions prior to CCM 3.1.1 / Nagios XI 5.8.2 contains multiple cross-site scripting (XSS) vulnerabilities in Overlay modals. Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.

The advisory is available at nagios.com. This vulnerability is handled as CVE-2021-47690 since 10/29/2025. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1059.007 by the MITRE ATT&CK project.

Upgrading to version 5.8.2 eliminates this vulnerability. The upgrade is hosted for download at nagios.com.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Log Management Software

Vendor

Nagios

Name

Version

License

commercial

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.4

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.4
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: XI 5.8.2

Timelineinfo

10/29/2025 CVE reserved
10/31/2025 +2 days Advisory disclosed
10/31/2025 +0 days VulDB entry created
11/08/2025 +8 days VulDB entry last update

Sourcesinfo

Advisory: nagios.com
Status: Confirmed

CVE: CVE-2021-47690 (🔒)
GCVE (CVE): GCVE-0-2021-47690
GCVE (VulDB): GCVE-100-330722

Entryinfo

Created: 10/31/2025 08:00
Updated: 11/08/2025 01:37
Changes: 10/31/2025 08:00 (69), 11/08/2025 01:37 (11)
Complete: 🔍
Cache ID: 216::103