CVE-2026-81945: PLANET IGS-5225-8P2T4S RCE Vulnerability

CVE-2026-81945 Overview

CVE-2026-81945 is a stack-based buffer overflow [CWE-121] in the web server component of the PLANET IGS-5225-8P2T4S industrial managed switch. The vulnerability affects V1 firmware versions before 1.2412b260707 and V2 firmware versions before 2.2412b260519. Insufficient bounds checking on data copied into a stack buffer allows a remote authenticated administrator to trigger memory corruption. Successful exploitation can cause a denial of service or lead to arbitrary code execution on the underlying operating system of the switch.

Critical Impact

An authenticated remote administrator can corrupt stack memory in the switch web server, potentially achieving code execution on a device that manages segmented industrial network traffic.

Affected Products

• PLANET IGS-5225-8P2T4S industrial managed switch (V1 hardware) with firmware before 1.2412b260707
• PLANET IGS-5225-8P2T4S industrial managed switch (V2 hardware) with firmware before 2.2412b260519
• Web management interface running on affected firmware builds

Discovery Timeline

• 2026-09-18 - CVE-2026-81945 published to the National Vulnerability Database
• 2026-09-22 - Last updated in NVD database

Technical Details for CVE-2026-81945

Vulnerability Analysis

The flaw resides in the embedded web server that provides administrative access to the IGS-5225-8P2T4S switch. The web server copies attacker-supplied input into a fixed-size stack buffer without validating the input length. When the input exceeds the buffer size, adjacent stack memory is overwritten, including saved return addresses and function pointers.

Exploitation requires valid administrator credentials, as reflected in the CVSS vector requiring high privileges. However, industrial switches often ship with weak or reused administrative credentials, and management interfaces are frequently exposed on flat operations networks. An attacker who gains administrator access can escalate impact from configuration tampering to full device compromise.

Root Cause

The root cause is missing bounds checking on data written to a stack-allocated buffer inside the web server binary. The developers used an unsafe copy operation without enforcing the destination buffer's capacity. This pattern maps directly to [CWE-121: Stack-based Buffer Overflow].

Attack Vector

The attack vector is network-based against the switch's HTTP management interface. An authenticated administrator submits a crafted request containing an oversized parameter that overflows the vulnerable stack buffer. The overwrite can crash the web server (denial of service) or, with careful payload construction, hijack control flow to execute arbitrary code on the switch operating system.

No public proof-of-concept exploit code has been released. See the VulnCheck Advisory on Planet IGS Buffer Overflow for further technical context.

Detection Methods for CVE-2026-81945

Indicators of Compromise

• Unexpected reboots or crashes of the IGS-5225-8P2T4S web management service
• HTTP POST or GET requests to the management interface containing abnormally long parameter values
• Administrative logins from unfamiliar source IP addresses preceding management-plane instability
• New or modified switch configuration entries that were not authorized through change management

Detection Strategies

• Monitor the switch management VLAN for HTTP traffic containing oversized parameters or malformed URIs targeting / endpoints on the web server
• Correlate administrative authentication events with subsequent web server errors, restarts, or loss of management connectivity
• Alert on any HTTP request to the switch management interface originating from outside approved administrator subnets

Monitoring Recommendations

• Forward switch syslog and authentication logs to a centralized SIEM for retention and correlation
• Track firmware version and build strings across the fleet to identify devices still running vulnerable builds
• Baseline normal web management traffic volume and content length, then alert on deviations

How to Mitigate CVE-2026-81945

Immediate Actions Required

• Upgrade V1 devices to firmware 1.2412b260707 or later and V2 devices to firmware 2.2412b260519 or later
• Rotate administrative credentials on all IGS-5225-8P2T4S switches and enforce unique, strong passwords
• Restrict access to the switch web management interface to a dedicated management network with an access control list
• Audit recent administrator activity and configuration changes for signs of unauthorized modification

Patch Information

PLANET Technology has released fixed firmware for both hardware revisions. Refer to the Planet Security Advisory for download instructions and release notes. Confirm the hardware revision (V1 or V2) before applying an update to avoid installing an incompatible image.

Workarounds

• Disable the HTTP web management interface where the device can be administered exclusively through the console or an out-of-band channel
• Place all industrial switch management interfaces on an isolated, firewalled management VLAN unreachable from OT process networks and the internet
• Enforce multi-factor authentication on jump hosts used to reach switch management interfaces to limit credential reuse risk

# Example ACL concept to restrict web management to a single admin host
# (syntax varies by switch CLI; consult vendor documentation)
access-list mgmt permit tcp host 10.10.0.25 any eq 80
access-list mgmt permit tcp host 10.10.0.25 any eq 443
access-list mgmt deny   tcp any any eq 80
access-list mgmt deny   tcp any any eq 443
interface vlan mgmt
  ip access-group mgmt in