Security readout for executives and security teams
Plain-English summary
Older versions of Nagios XI, a popular IT monitoring platform, contain a flaw in the web interface menu that lets an attacker plant malicious code in a logged-in user's browser. If an administrator clicks a tampered link or visits a poisoned page, the attacker can hijack the session, steal data shown in the console, or perform actions as that user.
Executive priority
Treat as a moderate, scheduled patching item rather than an emergency. Prioritize upgrades on any Nagios XI instance still on a pre-5.2.4 build, especially those reachable beyond the operations network, and fold remediation into the next standard maintenance window.
Technical view
Nagios XI before 5.2.4 fails to properly validate or encode user-supplied input handled by the Menu System component, producing a reflected or stored cross-site scripting condition (CWE-79). An authenticated attacker with low privileges can inject script that executes in another user's browser session, with user interaction required, leading to limited confidentiality and integrity impact on the subsequent system context per the CVSS 4.0 vector.
Likely exposure
Limited to organizations still running Nagios XI versions earlier than 5.2.4. Internet-exposed monitoring consoles raise exposure; internal-only deployments lower it. Any account with access to the menu system could stage the payload, and any other authenticated user who interacts with the affected view is a potential victim.
Exploitation context
No public evidence of active exploitation in the wild and the CVE is not listed in CISA KEV. The flaw requires an authenticated low-privileged attacker plus victim interaction, which constrains opportunistic abuse but remains realistic in shared NOC or MSP environments where multiple operators share the console.
Researcher notes
CVSS 4.0 vector indicates network attack, low complexity, low privileges, and required user interaction, with no impact on the vulnerable system itself but low confidentiality and integrity impact on the subsequent system. Affected version metadata in the bundle is sparse (defaultStatus unaffected, versions ["0"]); rely on the vendor changelog and VulnCheck advisory to confirm fixed build 5.2.4. No exploit code is referenced in the provided sources.
Mitigation direction
- Upgrade Nagios XI to version 5.2.4 or later per vendor changelog.
- Restrict console access to trusted administrators on a hardened management network.
- Review and remove unused low-privileged Nagios XI accounts.
- Enforce strong session controls and short admin session timeouts.
- Consult Nagios vendor guidance for any additional hardening recommendations.
Validation and detection
- Inventory all Nagios XI instances and record their installed versions.
- Flag any instance below version 5.2.4 as in scope for remediation.
- Confirm patch level after upgrade by checking the About or version page.
- Audit web access logs for unusual menu parameters or script-like payloads.
- Verify that the monitoring console is not unnecessarily exposed to the internet.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2016-15052 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.1 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
5.1MediumVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.nagios.com/changelog/nagios-xi/CVE reference · release-notes, patch
- https://www.vulncheck.com/advisories/nagios-xi-xss-via-menu-systemCVE reference · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.