CVE-2025-14857: Medium Vulnerability in Semtech LoRa LR11xxx Transceivers

An improper access control vulnerability exists in Semtech LoRa LR11xxx transceivers running early versions of firmware where the memory write command accessible via the physical SPI interface fails to enforce write protection on the program call stack. An attacker with physical access to the SPI interface can overwrite stack memory to hijack program control flow and achieve limited arbitrary code execution. However, the impact is limited to the active attack session: the device's secure boot mechanism prevents persistent firmware modification, the crypto engine isolates cryptographic keys from direct firmware access, and all modifications are lost upon device reboot or loss of physical access.

The severity level of this vulnerability is assessed as medium, with a CVSS score of 5.4. This score indicates that while the vulnerability poses a risk, it is not as critical as higher-severity vulnerabilities. Organizations utilizing affected Semtech devices should consider the implications of this vulnerability and assess their risk profile.

Risk to organizations includes potential unauthorized access to device functionality if an attacker gains physical access to the SPI interface. Given that the device's secure boot mechanism limits the impact of exploitation, the risk may be manageable, but organizations should remain vigilant.

Organizations should prioritize patching immediately.

Vulnerability Details

The vulnerability is characterized as an improper access control issue (CWE-123) within the Semtech LoRa LR11xxx transceivers. This vulnerability allows attackers with physical access to exploit the device through the SPI interface.

The vulnerability was published on April 7, 2026, and is currently awaiting analysis. The CVSS vector for this vulnerability is CVSS:4.0/AV:P/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H, indicating a physical attack vector with low complexity.

Technical Analysis

The root cause of this vulnerability lies in the failure to enforce write protection on the program call stack during memory write commands via the SPI interface. This oversight allows attackers to exploit the device's memory, leading to potential control flow hijacking.

The attack vector is categorized as physical, as it requires direct access to the device. The attack complexity is low, with no privileges or user interaction required for exploitation. The potential impacts on confidentiality, integrity, and availability are all rated as high, indicating serious implications for affected systems.

Risk & Impact Analysis

Organizations that deploy Semtech LoRa devices face a real-world risk from this vulnerability, particularly if these devices are located in accessible environments. The blast radius could extend significantly, depending on the operational context of the deployed transceivers.

Organizations should address this vulnerability in their priority patch cycle, considering the implications of potential unauthorized access to device functionality. With the CVSS score indicating a medium severity, while not critical, it still warrants attention to mitigate any risks effectively.

Affected Versions

All versions prior to vendor patch are affected by this vulnerability.

Mitigation & Remediation

To mitigate this vulnerability, organizations should apply the latest firmware updates provided by Semtech. Regularly check the vendor's security bulletins for updates, and ensure that any physical access to devices is controlled and monitored.

Organizations should validate remediation through penetration testing to identify similar weaknesses.

Detection Guidance

Organizations should monitor logs for any unauthorized access attempts on the SPI interface. Behavioral anomalies in device performance may indicate attempts to exploit this vulnerability. Additionally, network signatures related to device communications should be monitored for signs of tampering.

AppSecure Threat Intelligence Insight

The long-term significance of this vulnerability highlights a trend in physical access attacks on IoT devices. Security teams should prioritize securing physical interfaces and consider implementing stronger access controls and monitoring for their devices.

For organizations utilizing similar devices, understanding the importance of firmware updates and access control can prevent similar vulnerabilities. Continuous education and awareness programs can also enhance security postures.

Security teams should consider adopting a comprehensive approach to security that includes both offensive and defensive strategies. For more guidance, refer to red teaming services and AI security assessments to enhance your security framework.