CVE-2017-5139: An issue was discovered in Honeywell XL Web II controller XL1000C500 XLWebExe-2-01-00 and prior, and XLWeb...

Security readout for executives and security teams

Honeywell building controller software stored a password in plaintext and allowed any user to reveal it through a specific URL. For facilities using affected XL Web II or XLWeb 500 controllers, this could expose credentials that protect operational technology systems. Exposure is limited to organizations running the named Honeywell controller models and affected XLWebExe versions, especially if controller web interfaces are reachable by untrusted users or broad internal networks. Treat this as a high-priority OT credential exposure issue if affected controllers are deployed. The main business concern is unauthorized access to building automation systems through disclosed passwords, but source evidence does not confirm real-world exploitation. Mitigation focus: Check Honeywell and CISA ICS-CERT advisory guidance for vendor-approved updates or workarounds.; Identify affected controller models and XLWebExe versions in building automation environments.; Restrict controller web access to trusted management networks and authorized operators..

Prepared

Jun 13, 2026, 06:20 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.