CVE-2024-24731 Overview
CVE-2024-24731 is a stack-based buffer overflow [CWE-120] in Silicon Labs Gecko OS. The flaw resides in the implementation of the http_download command. The command fails to validate the length of user-supplied data before copying it into a fixed-size stack buffer. Network-adjacent attackers can exploit the vulnerability without authentication to execute arbitrary code in the context of the affected device.
Critical Impact
Unauthenticated attackers on the adjacent network can achieve arbitrary code execution on Silicon Labs Gecko OS devices by sending crafted input to the http_download command.
Affected Products
- Silicon Labs Gecko OS
- Devices running the Gecko OS command interface exposing http_download
- Embedded IoT deployments built on the Silicon Labs Gecko OS platform
Discovery Timeline
- 2025-01-31 - CVE-2024-24731 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-24731
Vulnerability Analysis
The vulnerability is a classic stack-based buffer overflow in the http_download command handler within Silicon Labs Gecko OS. When the command processes user-supplied arguments, it copies data into a stack-allocated buffer without first validating that the input length fits the destination.
An attacker who can reach the command interface over the adjacent network can supply an oversized argument. The excess data overwrites adjacent stack memory, including saved return addresses and control data. This corruption enables an attacker to redirect execution to attacker-controlled code and gain arbitrary code execution on the device.
Because Gecko OS is deployed on embedded and IoT hardware, successful exploitation grants control over device firmware behavior, network interfaces, and any sensor or actuator functions the device manages. The Zero Day Initiative Advisory ZDI-24-870 documents the underlying issue.
Root Cause
The root cause is missing input length validation before a stack buffer copy operation in the http_download command path [CWE-120]. Standard defensive practices such as bounds checking, length-limited copy routines, and stack canaries were not effective in preventing the overwrite of the return address.
Attack Vector
Exploitation requires network adjacency, meaning the attacker must reach the device over the same broadcast domain or a routable local network segment. No authentication or user interaction is required. The attacker sends a crafted http_download command containing an oversized argument to trigger the overflow and hijack control flow. See the Silicon Labs Community Post for vendor guidance.
Detection Methods for CVE-2024-24731
Indicators of Compromise
- Unexpected http_download command invocations originating from unknown adjacent hosts
- Device crashes, watchdog resets, or firmware anomalies following inbound command traffic
- Outbound connections from Gecko OS devices to unfamiliar hosts after receiving command input
- Abnormal changes to device configuration or firmware image checksums
Detection Strategies
- Monitor management interfaces on Gecko OS devices for oversized argument strings sent to command handlers
- Inspect network traffic on the adjacent segment for unauthorized access to Gecko OS command endpoints
- Baseline normal device behavior and alert on deviations in memory, uptime, or command activity
Monitoring Recommendations
- Enable syslog forwarding from Gecko OS devices to a centralized log platform for correlation
- Deploy network sensors on segments hosting embedded devices to capture command interface traffic
- Alert on repeated device reboots or unexpected firmware update attempts that may indicate exploitation attempts
How to Mitigate CVE-2024-24731
Immediate Actions Required
- Restrict network access to Gecko OS devices using VLAN segmentation and firewall rules that permit only trusted management hosts
- Disable the http_download command on devices where it is not required for operation
- Inventory all deployed Gecko OS devices and identify those exposing command interfaces to broader network segments
- Apply vendor-provided firmware updates as soon as they are available from Silicon Labs
Patch Information
Refer to the Silicon Labs Community Post for vendor guidance and firmware update availability. Coordinate with Silicon Labs support to obtain the corrected firmware image for affected product lines and confirm the fixed version applies to your device model.
Workarounds
- Place Gecko OS devices on isolated network segments accessible only to authorized management systems
- Block inbound access to the Gecko OS command interface at the network perimeter and internal choke points
- Implement network access control (NAC) policies to prevent unauthorized devices from joining segments hosting Gecko OS devices
- Monitor and rate-limit traffic to embedded device management ports to reduce the exploitation window
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
