CVE-2023-53003 is a high-severity use-after-free vulnerability in the Linux kernel affecting the Qualcomm Error Detection and Correction (EDAC) driver, specifically the interaction between the EDAC core and the LLCC (Last Level Cache Controller) driver. The root cause is improper handling of the llcc_driv_data pointer, which is allocated by the LLCC driver but incorrectly passed as the private driver info (pvt_info) to the EDAC core. During the release of the qcom_edac driver, this memory is freed, but when the driver is probed again, it attempts to access the freed memory, leading to a use-after-free condition (CWE-416). This can cause undefined behavior including kernel crashes, memory corruption, and potentially arbitrary code execution with kernel privileges. The vulnerability requires local access with low privileges (PR:L) and no user interaction (UI:N), but the attack vector is local (AV:L), meaning an attacker must have some level of access to the system to exploit it. The vulnerability impacts confidentiality, integrity, and availability (all rated high), making it a critical risk for affected systems. The fix involves changing the driver to reference llcc_driv_data via the platform_data pointer instead of passing it as pvt_info, preventing the premature freeing of memory and subsequent use-after-free. This vulnerability affects specific Linux kernel versions containing the vulnerable commit hash 27450653f1db0b9d5b5048a246c850c52ee4aa61 and related builds that include the Qualcomm EDAC driver implementation. No known exploits are currently reported in the wild, but the high CVSS score (7.8) and the nature of the bug warrant prompt patching.

For European organizations, this vulnerability poses a significant risk especially for those relying on Linux-based systems running on Qualcomm hardware platforms, such as embedded devices, IoT gateways, and certain network infrastructure components. Exploitation could allow local attackers to escalate privileges to kernel level, leading to full system compromise, data breaches, or disruption of critical services. This is particularly concerning for sectors with stringent data protection requirements like finance, healthcare, and critical infrastructure. The use-after-free can also cause system instability and denial of service, impacting availability of services. Given the widespread use of Linux in enterprise environments and embedded systems, unpatched devices could be targeted for lateral movement or persistence by attackers. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, as proof-of-concept exploits could emerge rapidly. Organizations with remote access or multi-user environments are at higher risk since local access is required for exploitation.

1. Apply the official Linux kernel patches that address CVE-2023-53003 as soon as they become available, ensuring the qcom_edac driver no longer passes llcc_driv_data as pvt_info. 2. For embedded or specialized devices using Qualcomm hardware and custom Linux kernels, coordinate with vendors to obtain updated firmware or kernel versions incorporating the fix. 3. Restrict local access to systems running vulnerable kernels by enforcing strict user privilege separation and limiting shell or console access. 4. Monitor system logs and kernel messages for anomalies or crashes related to the EDAC or LLCC drivers that could indicate exploitation attempts. 5. Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), Kernel Page Table Isolation (KPTI), and use of security modules (e.g., SELinux, AppArmor) to reduce exploitation likelihood. 6. Regularly audit and update Linux kernel versions across infrastructure to minimize exposure to known vulnerabilities. 7. For critical environments, consider implementing runtime integrity monitoring and intrusion detection systems capable of detecting kernel-level anomalies.