CVE-2025-37911 is a vulnerability identified in the Linux kernel's bnxt_en network driver, specifically related to the handling of firmware (FW) coredumps via the ethtool utility. The issue arises during the retrieval of FW coredumps using the ethtool -w command, where an out-of-bounds memcpy operation can occur. This vulnerability is caused by improper handling of the length of DMA'ed segment lists returned by the firmware. The bnxt_en driver allocates a buffer (info->dest_buf) based on the number of coredump segments reported by the firmware. However, the actual length of the DMA data returned by the firmware can exceed this allocated buffer size. When the driver copies the DMA'ed segment list into the buffer without properly capping the copy length, it results in memory corruption, as detected by the Kernel Electric Fence (KFENCE) debugging tool. The root cause lies in the discrepancy between the buffer size and the DMA length, which can lead to an out-of-bounds write. The vulnerability affects the code paths handling two firmware commands: HWRM_DBG_COREDUMP_LIST and HWRM_DBG_COREDUMP_RETRIEVE. The fix involves adjusting the buffer length for the HWRM_DBG_COREDUMP_RETRIEVE command earlier in the logic and capping the memcpy length to the buffer size, preventing overflow. This vulnerability is specific to certain Linux kernel versions containing the affected bnxt_en driver code. No known exploits are reported in the wild as of the publication date. The vulnerability does not require user interaction but does require access to ethtool commands, which typically need elevated privileges.

For European organizations, this vulnerability poses a risk primarily to systems running affected Linux kernel versions with the Broadcom NetXtreme-E (bnxt_en) network driver. The impact includes potential kernel memory corruption, which can lead to system instability, crashes (kernel panics), or denial of service (DoS). In worst-case scenarios, memory corruption vulnerabilities can be leveraged to execute arbitrary code in kernel context, potentially allowing privilege escalation or unauthorized control over the affected system. Given that many European enterprises, cloud providers, and critical infrastructure operators rely on Linux servers and network equipment using Broadcom NICs, exploitation could disrupt business operations, degrade service availability, or compromise sensitive data confidentiality and integrity. The vulnerability is exploitable locally by users with access to ethtool commands, which generally requires administrative or root privileges, limiting remote exploitation but increasing risk from insider threats or compromised accounts. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure. Systems involved in telecommunications, finance, government, and industrial control in Europe, which often use Linux-based infrastructure with Broadcom NICs, are particularly sensitive to such kernel-level vulnerabilities.

European organizations should take the following specific actions to mitigate CVE-2025-37911: 1) Identify and inventory all Linux systems using the bnxt_en driver, especially those with Broadcom NetXtreme-E network cards. 2) Apply the official Linux kernel patches that address this vulnerability as soon as they become available from trusted sources or Linux distributions. 3) If immediate patching is not feasible, restrict access to ethtool commands to trusted administrators only, minimizing the risk of local exploitation. 4) Monitor system logs and kernel messages for signs of memory corruption or abnormal behavior related to ethtool operations. 5) Implement strict privilege management and auditing to detect and prevent unauthorized use of ethtool or similar utilities. 6) Consider network segmentation and isolation of critical Linux servers to reduce exposure. 7) Engage with hardware and Linux distribution vendors for updated firmware and kernel releases that incorporate the fix. 8) Conduct regular vulnerability assessments and penetration testing focusing on kernel-level vulnerabilities and local privilege escalation vectors. These measures go beyond generic advice by emphasizing targeted identification of affected hardware, controlled access to vulnerable utilities, and proactive monitoring for exploitation indicators.