CVE-2025-24857: Denx U-boot RCE Vulnerability

CVE-2025-24857 Overview

CVE-2025-24857 is an improper access control vulnerability [CWE-284] affecting Universal Boot Loader (U-Boot) versions prior to 2017.11 running on Qualcomm IPQ-series chipsets. The flaw resides in how volatile memory containing boot code is protected during the early boot stage. An attacker with physical access to an affected device can leverage the weakness to execute arbitrary code in the bootloader context. Successful exploitation compromises the integrity of the boot chain on networking and embedded systems based on Qualcomm IPQ4019, IPQ5018, IPQ5322, IPQ6018, IPQ8064, IPQ8074, and IPQ9574 platforms.

Critical Impact
An attacker with physical access can execute arbitrary code in the bootloader, undermining secure boot guarantees and gaining persistent control over affected Qualcomm IPQ-based devices.

Affected Products

Denx U-Boot before version 2017.11
Qualcomm IPQ4019, IPQ5018, IPQ5322, and IPQ6018 chipsets
Qualcomm IPQ8064, IPQ8074, and IPQ9574 chipsets

Discovery Timeline

2025-12-10 - CVE-2025-24857 published to NVD
2026-01-21 - Last updated in NVD database

Technical Details for CVE-2025-24857

Vulnerability Analysis

The vulnerability stems from inadequate access control over volatile memory regions that hold boot code during U-Boot execution. U-Boot is widely used as the second-stage bootloader on embedded systems, including Qualcomm IPQ-based networking platforms. When boot code is staged in RAM without proper isolation, the contents become reachable to actors who can interact with the device at the hardware level. An attacker who modifies or substitutes the staged code can redirect execution before the operating system kernel takes control. This breaks the chain of trust established by secure boot and allows persistence below the operating system layer.

Root Cause

The defect maps to [CWE-284] Improper Access Control. U-Boot releases before 2017.11 do not enforce sufficient protections on the volatile memory window that contains boot code on the listed Qualcomm IPQ chips. The combination of bootloader behavior and chipset memory configuration leaves the staged code modifiable by a physically present adversary.

Attack Vector

Exploitation requires physical access to the target device, consistent with the CVSS attack vector of Physical. Typical attack paths against IPQ-based hardware include direct access to DRAM through hardware probes, exposed debug interfaces such as JTAG or UART, or removable storage that loads code into the affected memory region. After tampering with the boot code in volatile memory, the attacker triggers execution during the next boot cycle, gaining code execution at the bootloader privilege level. Because the scope is Changed, the impact propagates beyond the bootloader into the runtime operating system and user-space components loaded afterward. No verified public exploit code is available at the time of this writing. See the CISA ICS Advisory ICSA-25-343-01 for vendor-coordinated technical details.

Detection Methods for CVE-2025-24857

Indicators of Compromise

Unexpected modifications to bootloader images, U-Boot environment variables, or boot scripts on IPQ-based devices.
Device boot logs showing unsigned, unknown, or out-of-sequence stages prior to kernel handoff.
Evidence of physical tampering, including disturbed enclosures, exposed JTAG or UART headers, or unauthorized storage media.

Detection Strategies

Verify U-Boot version strings against a known-good baseline and flag any device running a release earlier than 2017.11.
Compare measured boot hashes or secure boot attestation results across the fleet to identify drift on IPQ4019, IPQ5018, IPQ5322, IPQ6018, IPQ8064, IPQ8074, and IPQ9574 platforms.
Inspect flash and bootloader regions during maintenance windows for unauthorized writes to boot partitions.

Monitoring Recommendations

Centralize bootloader and firmware integrity events into a SIEM and alert on version mismatches or attestation failures.
Monitor physical access logs, tamper switches, and console port activity for devices deployed in unattended or shared environments.
Track vendor advisories from Qualcomm and Denx for follow-on patches and configuration guidance.

How to Mitigate CVE-2025-24857

Immediate Actions Required

Inventory all devices using Qualcomm IPQ4019, IPQ5018, IPQ5322, IPQ6018, IPQ8064, IPQ8074, or IPQ9574 chipsets and identify those running U-Boot earlier than 2017.11.
Restrict physical access to affected hardware, including locking enclosures and disabling or sealing debug interfaces such as JTAG and UART.
Engage device vendors and integrators to obtain firmware updates that incorporate U-Boot 2017.11 or later with the required memory protections.

Patch Information

Upgrade U-Boot to version 2017.11 or later, integrated into a vendor-supplied firmware image that targets the affected Qualcomm IPQ chipsets. Because U-Boot is typically shipped as part of a device's firmware bundle, apply the OEM or ODM firmware release that incorporates the fix rather than rebuilding U-Boot in isolation. Refer to the CISA ICS Advisory ICSA-25-343-01 for coordinated vendor guidance.

Workarounds

Enforce strict physical security controls on deployed devices until firmware updates incorporating the fix are available.
Enable and validate secure boot, signed firmware, and runtime attestation features supported by the Qualcomm IPQ platform.
Disable unused boot sources and external debug interfaces in production configurations to reduce the attack surface.

bash

# Configuration example
# Verify the U-Boot version on an affected device and confirm it is 2017.11 or later
strings /dev/mtdblock0 | grep -i "U-Boot 20"
# Or from a running U-Boot console:
#   => version