CVE-2026-76943 Overview
CVE-2026-76943 is an authentication bypass vulnerability in the Xiiaozet LK100Wt device. The flaw resides in an administrative service that fails to properly enforce access controls. An unauthenticated remote attacker can reach privileged functionality and execute commands on the affected device. Successful exploitation leads to complete device compromise, including control over administrative operations. The weakness is classified under [CWE-288: Authentication Bypass Using an Alternate Path or Channel]. CISA published an Industrial Control Systems (ICS) advisory tracking this issue, indicating operational technology exposure.
Critical Impact
An unauthenticated network attacker can bypass authentication on the LK100Wt administrative service and execute arbitrary commands, resulting in full device takeover.
Affected Products
- Xiiaozet LK100Wt (administrative service)
- Specific firmware versions are not enumerated in the NVD entry; consult the CISA ICS Advisory ICSA-26-239-01
- Deployments exposing the administrative interface to untrusted networks
Discovery Timeline
- 2026-08-28 - CVE-2026-76943 published to NVD
- 2026-09-03 - Last updated in NVD database
Technical Details for CVE-2026-76943
Vulnerability Analysis
The Xiiaozet LK100Wt exposes an administrative service that does not correctly validate authentication before granting access to privileged commands. An attacker communicating over the network can invoke administrative functionality without presenting valid credentials. Once the attacker reaches these functions, the service permits command execution capabilities, effectively bridging an unauthenticated request into privileged operations on the device. This class of weakness typically arises when a secondary access path to protected functionality omits the checks enforced on the primary path.
Root Cause
The root cause is an authentication weakness within the administrative service, categorized as [CWE-288]. The service exposes privileged endpoints reachable through a path that bypasses the intended credential verification. Because the vulnerable device supports remote administrative operations, the missing enforcement translates directly into command execution and configuration control for any attacker with network reach.
Attack Vector
Exploitation requires only network access to the administrative service. No user interaction, no privileges, and no prior foothold are needed. An attacker sends crafted requests to the exposed administrative interface and obtains the ability to execute commands. In operational technology environments where LK100Wt devices are reachable from other network segments, an attacker pivoting inside the enterprise or ICS network can trigger the flaw remotely.
No verified proof-of-concept code has been published. See the CISA ICS Advisory and the GitHub CSAF file for authoritative technical detail.
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Stop Identity AttacksDetection Methods for CVE-2026-76943
Indicators of Compromise
- Unexpected administrative sessions on LK100Wt devices originating from unfamiliar internal or external IP addresses.
- Configuration changes, new user accounts, or unauthorized command execution recorded in device logs without a corresponding authenticated session.
- Outbound connections from the device to attacker-controlled infrastructure following administrative activity.
Detection Strategies
- Inspect network flows to and from LK100Wt devices for access to administrative service ports from non-authorized management hosts.
- Alert on administrative command invocation that lacks a preceding successful authentication event in device logs.
- Correlate ICS network telemetry with enterprise identifications to spot lateral movement toward LK100Wt endpoints.
Monitoring Recommendations
- Forward device syslog and administrative audit trails to a centralized SIEM for retention and correlation.
- Baseline normal management traffic patterns and alert on deviations such as new source subnets or off-hours activity.
- Monitor for repeated failed or anomalously successful administrative actions on affected devices.
How to Mitigate CVE-2026-76943
Immediate Actions Required
- Restrict network access to the LK100Wt administrative service using firewall rules or ACLs so only trusted management hosts can reach it.
- Place affected devices behind a segmented management VLAN and block administrative ports from general enterprise and internet traffic.
- Review device logs for signs of prior unauthorized administrative activity and rotate any credentials that may have been exposed.
Patch Information
The NVD entry does not list vendor patch URLs. Refer to the CISA ICS Advisory ICSA-26-239-01 for the vendor's mitigation guidance and any firmware updates. Apply vendor-supplied fixes as soon as they become available, and validate that the administrative service enforces authentication on all paths after updating.
Workarounds
- Disable the administrative service on devices where remote management is not required.
- Enforce network segmentation between IT and OT environments to limit reachability of the LK100Wt.
- Require VPN or jump-host access for any administrative session, and log all such connections centrally.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
