Security readout for executives and security teams
Plain-English summary
A flaw in older Nagios XI monitoring software lets a logged-in user hide malicious code inside a dashboard's background color setting. When another user opens that dashboard, the code runs in their browser. It does not directly take over servers, but it can hijack a victim's monitoring session and impersonate them inside the tool.
Executive priority
Schedule a routine upgrade to Nagios XI 5.7.2 or later during the next maintenance window. Treat as moderate hygiene risk, not an emergency, unless the dashboard is shared with privileged operators or exposed beyond trusted networks.
Technical view
Nagios XI prior to 5.7.2 fails to properly validate or escape user input in the dashboard background color setting, enabling stored cross-site scripting (CWE-79). An authenticated attacker with dashboard editing rights can inject script that executes in the browser of any user who later renders the affected dashboard, scoped within the Nagios XI session context.
Likely exposure
Any organization running Nagios XI versions prior to 5.7.2 with multiple users sharing or viewing dashboards is exposed. Risk concentrates in environments where lower-privileged Nagios accounts can author dashboards that higher-privileged operators or administrators later open in their browsers.
Exploitation context
No public reports of active exploitation and the CVE is not listed in CISA KEV. Exploitation requires an authenticated low-privileged user to set the malicious value and a victim to view the affected dashboard, limiting practical attack surface to insider or post-compromise scenarios per the cited advisory.
Researcher notes
CWE-79 stored/reflected XSS in the dashboard background color parameter. CVSS 4.0 vector indicates network attack, low privilege required, passive UI interaction, and limited subsequent confidentiality and integrity impact (SC:L/SI:L). The cited VulnCheck advisory and Nagios changelog point to 5.7.2 as the remediated build; no exploit chains, payloads, or PoC are referenced in the source bundle.
Mitigation direction
- Upgrade Nagios XI to version 5.7.2 or later per the vendor changelog.
- Restrict dashboard creation and editing rights to trusted operator accounts only.
- Place the Nagios XI console behind VPN or IP allowlist to limit attacker reach.
- Review and remove suspicious or unfamiliar dashboards authored by lower-privileged users.
- Monitor vendor advisories for any follow-up fixes referenced in the changelog.
Validation and detection
- Confirm installed Nagios XI build via the admin interface and compare against 5.7.2.
- Audit dashboards for unexpected characters or markup in background color or styling fields.
- Test in a non-production instance whether benign style payloads render unescaped in dashboards.
- Review Nagios audit and web server logs for unusual dashboard edits by low-privileged accounts.
- Verify post-upgrade that the dashboard background color input properly escapes injected markup.
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-2020-36864 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-dashboard-background-color-settingCVE 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.