External risk intelligence

AmpereOne Firmware Out-of-Bounds Write Vulnerability.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2025-62863

The vulnerability involves an SMC call to the UEFI-MM PCIe driver, which is a low-level firmware and hardware interface function. Such interfaces are not exposed to the public internet in standard deployments and are typically restricted to internal, local, or specialized developer access within the system architecture.

Out-of-bounds Write

Amperecomputing Ampereone A192 32m Firmware

before 5.4.5.1before 4.4.5.2before 3.5.9.3

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory details a critical vulnerability in AmpereOne devices. An improperly formed command could allow unauthorized control over the PCIe driver, potentially leading to significant data compromise and system disruption. The exposure is external, meaning it could be exploited over a network.

Flaw in device firmware could allow unauthorized control.
External access means it could affect systems remotely.
Confirm relevance and exposure for affected devices.

Attack Path

How an attacker could exploit the issue

An attacker could initiate a chain of actions to reach the vulnerable component within the device's firmware. This journey begins with an incorrectly formed call to the system management controller, targeting the UEFI-MM PCIe driver. If successful, this could lead to unauthorized modifications of memory within the PCIe driver's address space.

Entry condition: Network access to the device.
Trigger point: Malformed SMC call to UEFI-MM PCIe driver.
Resulting risk: Out-of-bounds write in PCIe driver.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could affect the integrity and availability of Ampere devices by allowing an out-of-bounds write in the PCIe driver's S-EL0 address space. This occurs when a specifically malformed SMC call is made to the UEFI-MM PCIe driver.

Device firmware integrity.
Malformed SMC call to driver.
Potential system instability or data corruption.

Operational Fix

Recommended remediation, mitigation, and detection steps

This critical vulnerability impacting AmpereOne devices requires coordination between infrastructure and platform teams, as they manage the firmware and underlying hardware. The immediate priority is to conduct an inventory of all affected AmpereOne devices, determine their business criticality and network exposure, and identify the specific system owners responsible for each. A risk-based remediation plan, including vendor coordination with Ampere Computing, should then be developed and executed.

Identify affected devices and ownership.
Verify network reachability and business impact.
Plan remediation with vendor support.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the AmpereOne product line and where is it used?

AmpereOne devices are high-performance ARM-based processors designed for cloud-native data centers. They serve as the core hardware, or CPUs, that power servers, handle high-density compute workloads, and manage infrastructure operations in modern computing environments.

What does CWE-787 mean for this CVE-2025-62863 vulnerability?

CWE-787 refers to an Out-of-Bounds Write. In the context of CVE-2025-62863, this means the software writes data beyond the intended boundaries of a memory buffer within the PCIe driver. This technical flaw allows for unauthorized memory access, which could disrupt normal system operations or compromise data integrity.

How is this vulnerability triggered in the firmware?

The issue is triggered when an incorrectly formed System Management Controller (SMC) call is sent to the UEFI-MM PCIe driver. This specifically requires interaction with that low-level interface; the vulnerability is not triggered by standard application-level tasks or typical data processing activities that do not involve this specific driver communication.

Is my AmpereOne system at risk from the internet?

While the CVE is classified as external, Halo Surface Signal notes it is very unlikely for these interfaces to be exposed to the public internet. The vulnerable UEFI-MM PCIe driver function is a low-level hardware interface generally restricted to internal or local system management, not direct network access.

What steps should I take if I use these devices?

Start by creating an inventory of your AmpereOne devices to identify which specific firmware versions are running. Once you have identified the hardware, coordinate with your platform and infrastructure teams to verify if those versions are impacted and plan for the necessary firmware updates provided by the vendor.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.