CVE-2024-26597 is a vulnerability identified in the Linux kernel, specifically within the Qualcomm RMNET driver component. The issue arises from an improper bounds check on the 'maxtype' variable used in parsing netlink attributes related to RMNET policy. The vulnerability manifests as a global out-of-bounds (OOB) read, where the kernel attempts to read memory beyond the allocated bounds of an array. This occurs because the 'rmnet_link_ops' variable assigns a larger 'maxtype' than the size of the destination array minus one, violating the expected constraint described in the 'nla_parse_nested_deprecated' function. The out-of-bounds read is detected by Kernel Address Sanitizer (KASAN) during validation of netlink attributes, indicating a memory safety violation. The bug trace shows that the issue occurs during the processing of rtnetlink messages, which are used for network configuration and management in Linux. The vulnerability affects Linux kernel version 6.1.0 and likely others with the same RMNET implementation. The root cause is a logic error in the bounds checking of netlink attribute parsing, leading to a read from an invalid memory address. While the vulnerability is a read (not write) out-of-bounds, such flaws can potentially be leveraged for information disclosure or to cause kernel crashes (denial of service). The vulnerability does not require user interaction but does require the ability to send crafted netlink messages to the kernel, which typically requires local or privileged access. No known exploits are reported in the wild as of the publication date. No CVSS score has been assigned yet. The fix involves correcting the 'maxtype' value to be the length of the destination array minus one, ensuring proper bounds checking and preventing the out-of-bounds read.

For European organizations, this vulnerability poses a risk primarily to systems running vulnerable Linux kernel versions with Qualcomm RMNET drivers, commonly found in embedded devices, mobile gateways, and network infrastructure equipment. The out-of-bounds read could be exploited to leak kernel memory contents, potentially exposing sensitive information or enabling further kernel-level attacks. Additionally, crafted netlink messages could trigger kernel crashes, leading to denial of service conditions impacting availability of critical network services. Organizations relying on Linux-based network appliances, IoT devices, or mobile network infrastructure could face operational disruptions or data exposure if exploited. Given the kernel-level nature of the flaw, successful exploitation could undermine system integrity and confidentiality. Although exploitation requires local or privileged access to send netlink messages, attackers who gain such access (e.g., via compromised accounts or lateral movement) could leverage this vulnerability to escalate privileges or disrupt services. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially in targeted attacks against telecom or network providers in Europe. The vulnerability's impact is heightened in environments with stringent availability and data protection requirements, such as financial institutions, critical infrastructure, and telecom operators.

European organizations should prioritize updating Linux kernels to versions where this vulnerability is patched, ensuring the RMNET driver code includes the corrected bounds checking. Specifically, apply vendor-supplied kernel updates or mainline Linux kernel patches that fix the 'maxtype' assignment in the RMNET policy parsing code. For embedded or network devices where kernel updates are delayed or unavailable, consider implementing network segmentation and strict access controls to limit which users or processes can send netlink messages, reducing the attack surface. Employ kernel hardening techniques such as Kernel Address Sanitizer (KASAN) in testing environments to detect similar memory safety issues proactively. Monitor system logs for unusual rtnetlink activity or kernel warnings indicative of exploitation attempts. Additionally, restrict local user privileges to prevent unauthorized netlink message injection, and use mandatory access control frameworks (e.g., SELinux, AppArmor) to constrain network configuration operations. Conduct thorough inventory and risk assessment of Linux-based network devices using Qualcomm RMNET drivers to identify vulnerable assets and prioritize patching. Finally, maintain up-to-date incident response plans to quickly address potential kernel-level compromises.