Horizon Alert
Summary of the vulnerability and why it matters
This advisory concerns a flaw in the Zephyr RTOS that could allow an attacker to read sensitive device memory or cause a device to crash. The vulnerability lies within the LwM2M firmware update feature, which handles network URIs. If a malicious URI is provided, it can lead to an out-of-bounds read of adjacent memory, potentially exposing data or causing a denial-of-service condition. The main concern is confirming the relevance and exposure of this feature within your deployed devices.
- Flaw in firmware updates can expose memory or crash devices.
- Matters due to potential for data leaks or service disruption.
- Confirm relevance and exposure of the firmware update feature.
Attack Path
How an attacker could exploit the issue
An attacker can potentially trigger this vulnerability by sending a crafted firmware update URI to a vulnerable device. This URI, when written to a specific object on the device, is copied into a buffer without proper length checking. Subsequent processing of this improperly copied URI can lead to an out-of-bounds read, potentially exposing device memory or causing the device to crash.
- No authentication required to access.
- Triggered by writing a malicious URI.
- Information disclosure and denial of service.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability could expose sensitive information from a device's memory and cause it to crash. When a specially crafted firmware update URI is provided to the LwM2M Firmware Update object, the system may copy more data than its buffer can hold, leading to an out-of-bounds read. This read can disclose adjacent memory contents in network requests and potentially halt the device's operation.
- Device memory could be disclosed.
- Malformed URIs could trigger buffer overflows.
- Information disclosure and denial of service.
Operational Fix
Recommended remediation, mitigation, and detection steps
The Zephyr RTOS component responsible for LwM2M firmware updates is affected, potentially impacting IoT device management. Owners of systems utilizing this component, particularly those exposed to LwM2M management servers or on-path attackers without strong DTLS, should first identify all instances of the affected Zephyr versions, assess their network exposure and criticality, and then coordinate with the relevant platform or embedded development teams to plan remediation.
- Own by platform/embedded development teams.
- Verify device network exposure and criticality.
- Plan and coordinate remediation actions.
