Full Report
Tricking a plug with a too-long name could lead to buffer overflows, injections.
Analysis Summary
# Vulnerability: Wemo Mini Smart Plug V2 Buffer Overflow Allowing Remote Operation
## CVE Details
- CVE ID: [CVE-2023-27217]
- CVSS Score: Information not explicitly provided, but the context suggests **High** severity due to remote code execution potential.
- CWE: Buffer Overflow (Implied)
## Affected Systems
- Products: Wemo Mini Smart Plug V2
- Versions: Not explicitly listed, but affects the V2 hardware generation.
- Configurations: Devices connected to the wider Internet, or accessible from a network where an attacker can issue commands using third-party tools like `pyWeMo`.
## Vulnerability Description
The Wemo Mini Smart Plug V2 suffers from a buffer overflow vulnerability triggered by providing a device name longer than its internal 30-character limit. This limit is only enforced by Wemo's own applications, not the underlying handling of network commands. By using third-party tools, an attacker can send an excessively long name, causing a buffer overflow that allows for the injection of operable code. If the device is internet-facing, this leads to remote code execution (RCE). Furthermore, established community tools like `pyWeMo` can issue commands to toggle the device without requiring any password or authentication, regardless of the specific fix status of other vulnerabilities.
## Exploitation
- Status: Proof of Concept (PoC) appears available via the research conducted by Sternum and the use of tools like `pyWeMo`. The mechanism relies on controlled input, making exploitation predictable.
- Complexity: **Medium** (Requires knowledge of the device protocol and use of external tools, but the trigger condition is simple—a long name).
- Attack Vector: **Network** (Attacker can interact over the local network or the internet if the device is exposed).
## Impact
- Confidentiality: **High** (If RCE is achieved, sensitive device information could be exposed).
- Integrity: **High** (Arbitrary code execution allows the attacker to control the device functionality).
- Availability: **High** (Device could be rendered inoperable or endlessly toggled).
## Remediation
### Patches
- **None available.** Belkin/Wemo has stated that they **will not** be patching this vulnerability because the Wemo Mini Smart Plug V2 is "at the end of its life."
### Workarounds
- **Network Segmentation:** Isolate vulnerable units onto a separate subnet away from sensitive devices.
- **Firewalling:** Prevent external or untrusted internal network access to the device's network port (if possible, depending on required functionality).
- **Avoid Cloud Exposure:** Avoid exposing the device to the wider Internet, as the vulnerability could be triggered via Wemo's cloud interface.
- **Avoid Third-Party Tools:** Do not use unauthenticated community tools interacting with the device protocol unless strictly necessary and understood.
## Detection
- **Indicators of Compromise (IoCs):** Unexpected device behavior (e.g., unexpected toggling), high outbound network traffic from the device not attributable to normal operation.
- **Detection Methods and Tools:** Network traffic monitoring for unusually long strings sent to the device over its operating ports (typically TCP/UDP ports used for local control, often associated with UPnP or proprietary protocols).
## References
- Sternum Disclosure (Implied): [cve.report/CVE-2023-27217]
- Research Details (Implied): [sternumiot.com/iot-blog/mini-smart-plug-v2-vulnerability-buffer-overflow/]
- Community Tool (Contextual): [github.com/pywemo/pywemo]
- Vendor Advisory (Contextual Status): Ars Technica reports Belkin acknowledged and declined to fix.