CVE-2025-68657 is a double free vulnerability identified in the Espressif ESP-IDF USB Host Human Interface Device (HID) driver, specifically in versions prior to 1.1.0. The vulnerability stems from a race condition where both the USB event callback and user code can concurrently invoke hid_host_device_close(), leading to the same usb_transfer_t memory being freed twice. This occurs because the shared hid_iface_t state is accessed without proper synchronization or locking mechanisms, allowing simultaneous teardown of a READY interface. The double free results in heap metadata corruption within the ESP USB host stack, which can cause undefined behavior including crashes, memory corruption, or potentially arbitrary code execution. The vulnerability affects embedded devices using Espressif's USB host stack for HID devices, commonly found in IoT and embedded systems. The CVSS v3.1 score of 6.4 reflects medium severity, with attack vector being physical or local (AV:P), high attack complexity (AC:H), no privileges required (PR:N), and no user interaction (UI:N). The impact covers confidentiality, integrity, and availability, as exploitation could allow attackers to disrupt device operation or manipulate data. The issue was publicly disclosed on January 12, 2026, and fixed in ESP-IDF version 1.1.0. No known exploits have been reported in the wild, but the vulnerability poses a risk to devices that have not been updated. The root cause relates to improper concurrency control (CWE-667) and double free (CWE-415) in the USB host stack implementation.

For European organizations, the impact of CVE-2025-68657 primarily concerns embedded and IoT devices using Espressif ESP-IDF USB host stacks, especially those interfacing with HID devices. Exploitation could lead to device crashes, denial of service, or potentially arbitrary code execution, compromising device availability and integrity. This could disrupt critical infrastructure, industrial control systems, or consumer IoT deployments. Confidentiality may also be at risk if attackers leverage heap corruption to execute code or access sensitive data. Given the widespread use of Espressif chips in IoT devices, sectors such as manufacturing, smart cities, healthcare, and automotive in Europe could be affected. The requirement for physical or local access to the USB host interface limits remote exploitation but does not eliminate risk in environments where attackers have proximity or insider access. The vulnerability could facilitate lateral movement or persistence in targeted attacks. Organizations relying on Espressif-based devices should assess their exposure and prioritize patching to maintain operational security.

1. Upgrade all Espressif ESP-IDF USB Host HID driver instances to version 1.1.0 or later, where the vulnerability is fixed. 2. Implement strict access controls to USB host interfaces on embedded devices to prevent unauthorized physical or logical access. 3. Employ runtime monitoring and anomaly detection on USB host activity to identify unusual device teardown or memory corruption events. 4. For devices that cannot be immediately updated, consider disabling USB host HID functionality if not required. 5. Conduct thorough security audits of IoT and embedded device firmware to identify usage of vulnerable ESP-IDF versions. 6. Enforce network segmentation and physical security controls to limit attacker proximity to vulnerable devices. 7. Collaborate with device manufacturers to ensure timely firmware updates and vulnerability disclosures. 8. Integrate vulnerability management processes that track Espressif component versions and patch status across deployed devices.