CVE-2025-8627 Overview
CVE-2025-8627 affects the TP-Link KP303 (US) Smartplug in firmware versions before 1.1.0. The device accepts unauthenticated protocol commands over the adjacent network, allowing attackers to trigger unintended power-off conditions and obtain leaked device information. The flaw maps to [CWE-306], Missing Authentication for a Critical Function. An attacker on the same Wi-Fi or local network segment can issue commands without supplying credentials. This affects availability of the connected load and confidentiality of device data exposed by the protocol handler. TP-Link addressed the issue in firmware 1.1.0.
Critical Impact
Adjacent-network attackers can power off connected devices and harvest device information without authentication, undermining both availability and confidentiality of the smart plug deployment.
Affected Products
- TP-Link KP303 (US) Smartplug hardware revision 2.0
- TP-Link KP303 firmware versions prior to 1.1.0
- Deployments exposing the KP303 management protocol on shared Wi-Fi or LAN segments
Discovery Timeline
- 2025-08-25 - CVE-2025-8627 published to NVD
- 2025-09-15 - Last updated in NVD database
Technical Details for CVE-2025-8627
Vulnerability Analysis
The KP303 Smartplug exposes a network management protocol used by the TP-Link Kasa mobile application and cloud services. The protocol handler processes specific command frames without first verifying that the sender holds a valid session or device pairing token. An attacker connected to the same broadcast domain can craft and send these frames directly to the device. The device honors the commands as if they originated from a paired controller. This permits forced power-off of any outlet on the strip and the retrieval of identifying device metadata returned in protocol responses.
Root Cause
The root cause is Missing Authentication for a Critical Function [CWE-306]. The firmware does not enforce authentication on protocol commands that change power state or return device information. Authorization checks were apparently assumed to be satisfied by network locality rather than by cryptographic session binding. Any host able to reach the device on its listening port can invoke privileged operations.
Attack Vector
Exploitation requires adjacent-network access, such as a shared Wi-Fi SSID, a guest network bridged to the IoT VLAN, or a compromised device on the same LAN. The attacker enumerates KP303 devices via standard discovery traffic, then transmits the unauthenticated command frames directly to each device IP. No user interaction is required, and no prior pairing with the target is needed. The vulnerability cannot be reached purely from the public internet unless the LAN is otherwise exposed. Verified exploit code is not publicly available at the time of writing.
Detection Methods for CVE-2025-8627
Indicators of Compromise
- Unexpected power-off events recorded in the Kasa app activity log for KP303 outlets
- Protocol traffic to KP303 devices originating from hosts that are not the registered Kasa controller or cloud endpoint
- Discovery scans targeting common Kasa/KP303 ports from unmanaged or guest-network hosts
Detection Strategies
- Inspect LAN traffic for unauthenticated Kasa protocol command frames sent to KP303 IP addresses outside expected controller flows
- Correlate smart plug state changes with the source host of the controlling traffic to surface unauthorized controllers
- Alert on new MAC or IP addresses initiating sessions to IoT devices on segmented IoT VLANs
Monitoring Recommendations
- Enable wireless intrusion detection on SSIDs that host KP303 devices to flag rogue clients
- Log DHCP leases and ARP activity on IoT subnets to detect unauthorized adjacent hosts
- Forward IoT VLAN flow records to a SIEM and baseline normal Kasa controller traffic for anomaly detection
How to Mitigate CVE-2025-8627
Immediate Actions Required
- Upgrade all TP-Link KP303 (US) Smartplug devices to firmware version 1.1.0 or later through the Kasa application
- Place KP303 devices on a dedicated IoT VLAN or SSID isolated from user, server, and guest networks
- Restrict inbound traffic to KP303 devices so that only the authorized Kasa controller host can initiate sessions
Patch Information
TP-Link released firmware 1.1.0 for the KP303 (US) Smartplug, which addresses the missing authentication on protocol commands. Update instructions and the firmware package are referenced in the TP-Link Support FAQ. Apply the update through the Kasa mobile application or via the TP-Link support download portal.
Workarounds
- Disable the Kasa local control protocol on the network by blocking the device management port at the VLAN gateway until firmware is updated
- Power down or disconnect KP303 units from the network if they cannot be patched promptly and isolation is not feasible
- Enforce WPA3 or WPA2-Enterprise on the IoT SSID to reduce the population of hosts able to reach the device
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
