CVE-2026-41918 Overview
CVE-2026-41918 affects Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) industrial Ethernet switches in all versions prior to V4.0. The device stores sensitive information in the browser cache when an authenticated user modifies specific configurations. An authenticated attacker with access to the browser can retrieve this cached data and expose configuration details. The weakness is classified under [CWE-525: Use of Web Browser Cache Containing Sensitive Information].
Critical Impact
An authenticated attacker with access to a user's browser cache can recover sensitive configuration data from RUGGEDCOM RST2428P management sessions.
Affected Products
- Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) — all versions prior to V4.0
Discovery Timeline
- 2026-06-02 - CVE-2026-41918 published to NVD
- 2026-06-02 - Last updated in NVD database
Technical Details for CVE-2026-41918
Vulnerability Analysis
The RUGGEDCOM RST2428P web management interface fails to instruct the browser to avoid caching responses that contain sensitive configuration data. When an authenticated administrator modifies specific configurations through the web UI, the browser writes the responses to its local cache. The cached artifacts persist after the session ends and remain readable from disk.
The vulnerability is an information disclosure issue rather than a code execution flaw. It requires an authenticated session and user interaction to populate the cache. An attacker who later gains access to the workstation, the browser profile, or a forensic image can extract the cached configuration material without re-authenticating to the switch.
The Siemens advisory SSA-253495 tracks this issue along with the corrective firmware update. The EPSS probability is 0.031%, indicating low likelihood of opportunistic exploitation in the wild.
Root Cause
The root cause is missing or insufficient HTTP cache-control directives on responses that contain sensitive data. Headers such as Cache-Control: no-store, Pragma: no-cache, and appropriate Expires values are required to prevent the browser from persisting these responses to disk.
Attack Vector
Exploitation requires network access to the device, an authenticated low-privileged user session, and user interaction to trigger the configuration change. After the legitimate session, an attacker with local or remote access to the browser cache reads the stored artifacts. Multi-user workstations, shared jump hosts, and recovered disk images are realistic exposure scenarios.
No public proof-of-concept code or exploit is available. The vulnerability is described in prose by the vendor advisory and does not require crafted payloads. See the Siemens Security Advisory SSA-253495 for technical details.
Detection Methods for CVE-2026-41918
Indicators of Compromise
- Presence of RUGGEDCOM RST2428P web UI responses inside browser cache directories such as Chromium's Cache_Data or Firefox's cache2/entries.
- Unexpected access to user profile directories on workstations used to administer RUGGEDCOM devices.
- Forensic recovery of configuration fragments containing RUGGEDCOM management URLs from endpoint storage.
Detection Strategies
- Inspect HTTP responses from the RUGGEDCOM management interface for missing Cache-Control: no-store and Pragma: no-cache headers.
- Hunt endpoint telemetry for non-administrative processes reading browser cache directories on hosts that manage industrial switches.
- Correlate authentication events on RUGGEDCOM devices with subsequent file access to the administrator's browser profile.
Monitoring Recommendations
- Log and review all administrative sessions to RUGGEDCOM RST2428P devices, including source workstation identity.
- Monitor for browser profile exfiltration patterns such as archiving of AppData\Local\Google\Chrome\User Data directories.
- Alert on unauthorized logons to engineering workstations that hold cached RUGGEDCOM management content.
How to Mitigate CVE-2026-41918
Immediate Actions Required
- Upgrade RUGGEDCOM RST2428P firmware to V4.0 or later as published in Siemens advisory SSA-253495.
- Clear browser caches on every workstation used to administer affected RUGGEDCOM devices.
- Restrict administrative access to the RUGGEDCOM web interface to dedicated, hardened management hosts.
Patch Information
Siemens has published fixed firmware for RUGGEDCOM RST2428P in version V4.0 and later. Refer to the Siemens Security Advisory SSA-253495 for download instructions and validation guidance.
Workarounds
- Use the browser in private or incognito mode when accessing the RUGGEDCOM web management interface so cache contents are not written to disk.
- Manually clear browser cache and history immediately after each administrative session on the device.
- Limit management access to isolated jump hosts that are not used for general-purpose browsing or shared user activity.
# Configuration example: clear Chromium browser cache after RUGGEDCOM admin session (Linux)
rm -rf ~/.cache/google-chrome/Default/Cache/*
rm -rf ~/.cache/chromium/Default/Cache/*
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
