CVE-2025-67841 Overview
CVE-2025-67841 is an algorithmic complexity vulnerability affecting Nordic Semiconductor IronSide Secure Element (SE) for the nRF54H20 system-on-chip. Versions prior to 23.0.2+17 contain a flaw classified under [CWE-407] that an attacker can trigger remotely without authentication or user interaction. The flaw enables a denial-of-service condition by forcing the affected component into worst-case algorithmic behavior. Nordic Semiconductor documented the issue in a security advisory, and the vulnerability was published to the National Vulnerability Database (NVD) on April 15, 2026.
Critical Impact
A network-reachable attacker can exhaust processing resources on the nRF54H20 IronSide SE, resulting in availability loss for the secure element and dependent applications.
Affected Products
- Nordic Semiconductor IronSide SE for nRF54H20 — versions prior to 23.0.2+17
- nRF54H20 SoC platforms relying on the affected IronSide SE firmware
- Embedded and IoT products that integrate the vulnerable IronSide SE component
Discovery Timeline
- 2026-04-15 - CVE-2025-67841 published to NVD
- 2026-04-17 - Last updated in NVD database
Technical Details for CVE-2025-67841
Vulnerability Analysis
The vulnerability is an algorithmic complexity flaw, tracked under [CWE-407] (Inefficient Algorithmic Complexity). Specially crafted input causes the IronSide SE firmware to enter a processing path with disproportionately high computational cost. The result is sustained CPU consumption that prevents the secure element from servicing legitimate requests.
The attack vector is network-based and requires no authentication or user interaction. Confidentiality and integrity are not affected, but availability degradation can disrupt cryptographic services, secure boot, key storage, and other functions that depend on IronSide SE on the nRF54H20. In embedded contexts, this can cascade into broader device or fleet outages.
Root Cause
The root cause lies in algorithm selection or input handling within IronSide SE that does not bound worst-case execution time. When an attacker controls the inputs to the affected routine, the runtime scales non-linearly, consuming resources on the secure element. Nordic Semiconductor addressed the flaw in IronSide SE release 23.0.2+17.
Attack Vector
An unauthenticated remote attacker sends crafted requests that reach the IronSide SE processing surface on the nRF54H20. The crafted inputs steer execution into the high-complexity code path. Repeated or sustained submission of such inputs holds the secure element in a busy state, denying service to legitimate workloads.
No public proof-of-concept or exploit code is available for CVE-2025-67841 at the time of writing. Refer to the Nordic Semiconductor Security Advisory for vendor-supplied technical detail.
Detection Methods for CVE-2025-67841
Indicators of Compromise
- Sustained high CPU utilization on the nRF54H20 IronSide SE without a corresponding legitimate workload.
- Increased latency or timeouts in cryptographic operations, secure boot checks, or attestation flows served by IronSide SE.
- Repeated inbound requests from the same source containing unusual or malformed parameters targeting the secure element interface.
Detection Strategies
- Inventory all deployed nRF54H20 devices and identify those running IronSide SE versions earlier than 23.0.2+17.
- Instrument device telemetry to alert on abnormal IronSide SE processing time and request error rates.
- Correlate network traffic targeting device management or cryptographic endpoints with secure element performance metrics.
Monitoring Recommendations
- Forward device health and IronSide SE performance counters to a centralized logging or SIEM platform for trend analysis.
- Establish baselines for normal request volume and processing time, and alert on statistically significant deviations.
- Monitor vendor advisories from Nordic Semiconductor for follow-on guidance or updated firmware releases.
How to Mitigate CVE-2025-67841
Immediate Actions Required
- Upgrade Nordic Semiconductor IronSide SE for nRF54H20 to version 23.0.2+17 or later on all affected devices.
- Identify network paths that expose the IronSide SE interface and restrict them to trusted sources until patching is complete.
- Review fleet management tooling to confirm firmware rollout coverage and verify successful update reporting.
Patch Information
Nordic Semiconductor has released IronSide SE 23.0.2+17, which remediates the algorithmic complexity issue. Patch details and distribution guidance are provided in the Nordic Semiconductor Security Advisory. Vendor documentation is available on the Nordic Semiconductor Homepage.
Workarounds
- Apply network segmentation and firewall rules to limit reachability of the nRF54H20 IronSide SE interface to authorized hosts.
- Rate-limit inbound requests to device endpoints that interact with the secure element to reduce exposure to repeated abusive inputs.
- Implement watchdog or recovery routines that restart stalled secure element workflows where supported by the platform.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
