CVE-2025-37927 is a vulnerability identified in the Linux kernel specifically within the IOMMU AMD driver code, in the function parse_ivrs_acpihid. The flaw arises from improper string parsing logic that leads to a potential buffer overflow in the handling of 'hid' and 'uid' buffers. The vulnerability is due to an insufficient length check: the code compares the total string length against a constant ACPIID_LEN but fails to separately validate the lengths of the individual 'hid' and 'uid' strings. For example, if the 'hid' string length is 4 and the 'uid' string length is 260, the total string length check may pass, but the 'uid' buffer, which is only 256 bytes, will overflow. Similarly, a 'hid' string of length 13 combined with a 'uid' string of length 250 also causes overflow. This buffer overflow can lead to memory corruption, potentially allowing an attacker to execute arbitrary code or cause denial of service by crashing the kernel. The vulnerability was discovered by the Linux Verification Center using static analysis tools (SVACE). It affects multiple versions of the Linux kernel identified by the commit hash ca3bf5d47cec8b7614bcb2e9132c40081d6d81db. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The fix involves separately checking the lengths of the 'hid' and 'uid' strings to ensure they do not exceed their respective buffer sizes, thereby preventing overflow.

For European organizations, this vulnerability poses a significant risk especially to those relying on Linux-based systems in their infrastructure, including servers, cloud environments, and embedded devices using AMD IOMMU technology. Exploitation could lead to kernel-level compromise, allowing attackers to gain elevated privileges, execute arbitrary code, or cause system crashes resulting in denial of service. This can disrupt critical services, data processing, and availability of IT resources. Given the widespread use of Linux in European enterprises, government agencies, and critical infrastructure sectors such as finance, telecommunications, and manufacturing, the impact could be severe. Additionally, organizations using AMD hardware with IOMMU enabled are particularly at risk. The absence of known exploits currently provides a window for proactive patching, but the potential for future exploitation remains high. Confidentiality, integrity, and availability of systems could all be compromised if the vulnerability is exploited.

European organizations should prioritize applying the official Linux kernel patches that address this vulnerability as soon as they are released. Until patches are deployed, organizations should audit their Linux systems to identify those running affected kernel versions and using AMD IOMMU features. Disabling IOMMU functionality temporarily may reduce exposure but could impact system performance or functionality. Employing kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), stack canaries, and strict memory protections can help mitigate exploitation risk. Monitoring system logs and kernel messages for anomalous behavior related to IOMMU or ACPI parsing is recommended. Additionally, organizations should implement strict access controls to limit unprivileged user ability to trigger this code path. Regular vulnerability scanning and integration of static analysis tools similar to SVACE in development pipelines can help detect similar issues early. Finally, maintaining an up-to-date inventory of Linux kernel versions and hardware configurations will facilitate rapid response to such vulnerabilities.