GitHub Advisoryadvisory · npm

GHSA-c7hr-448w-65px MeshCentral has unsanitized data fields

HIGH Published 2026-08-18 Modified 2026-08-18 Official page ↗
Ecosystem
npm
Packages
meshcentral
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
Weaknesses
CWE-20, CWE-74
Reviewed
2026-08-18

Affected packages

• npm meshcentral: < 1.1.60 → fixed in 1.1.60

Description

Description A rogue or compromised MeshAgent can inject arbitrary HTML/JavaScript via the osdesc (OS description) field in its coreinfo message. The server stores this value with zero HTML sanitization (meshagent.js:1903 only checks typeof == 'string'). When an admin views the device details panel, the value is rendered via addDeviceAttribute() → QH() which sets innerHTML, executing the payload in the admin's browser session. The main management UI CSP includes 'unsafe-inline' (webserver.js:7072), so inline event handlers and script execution are unrestricted. Technical Details ```javascript // meshagent.js:1903 -- Agent input, only type check if (typeof command.osdesc == 'string') { device.osdesc = command.osdesc; change = 1; } // default3.handlebars:8713 -- Rendered WITHOUT EscapeHtml() if (node.osdesc) { x += addDeviceAttribute("Operating System", node.osdesc); } // addDeviceAttribute() interpolates into HTML string, QH() sets innerHTML // INCONSISTENCY: Same field IS escaped elsewhere: // Line 13529: addDetailItem("Version", EscapeHtml(node.osdesc), s) // Line 5760: EscapeHtml(node.osdesc ? node.osdesc : '') ``` Additional unescaped agent fields: • node.name unescaped in sharing dialog (line 4695), user group list (line 18625), permission dialogs (lines 18675, 19413) -- HIGH • cpuinfo.thermals[].InstanceName attribute injection (line 13502) -- MEDIUM • volumes[].name unescaped in file browser (line 12612) -- MEDIUM No server-side defense: CloneSafeNode() strips secrets but not XSS. validateObjectForMongo() only enforces length limits (1024 chars). No HTML sanitation exists anywhere in the agent→DB→UI pipeline. Proof of Concept Rogue agent sends via WebSocket: ```json { "action": "coreinfo", "osdesc": "", "name": "Legit-PC" } ``` Payload fires when any admin views the device details panel. No click required.

Related

Weakness · CWE (2)

  • CWE-20 Improper Input Validation weakness
  • CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component weakness

References