CVE-2021-47571 is a use-after-free vulnerability identified in the Linux kernel, specifically within the staging driver rtl8192e, which supports certain Realtek wireless network adapters. The vulnerability arises in the _rtl92e_pci_disconnect() function, where the free_rtllib() function frees a device pointer ('dev'), but subsequent code attempts to access this freed pointer, leading to a use-after-free condition. This type of vulnerability can cause undefined behavior including system crashes, memory corruption, or potentially arbitrary code execution if exploited. The vulnerability is rooted in improper memory management and pointer handling in the driver code. The issue has been addressed by re-arranging the code to ensure that the freed pointer is not accessed after being released. The affected versions appear to be specific commits or builds of the Linux kernel containing the vulnerable rtl8192e driver code. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The vulnerability was published on May 24, 2024, and is considered a kernel-level flaw affecting Linux systems using the vulnerable wireless driver.

For European organizations, the impact of CVE-2021-47571 depends largely on the deployment of Linux systems utilizing the rtl8192e wireless driver. Many enterprises and public sector organizations in Europe rely on Linux-based infrastructure for servers, desktops, and embedded devices. If these systems use the affected Realtek wireless adapters, the vulnerability could allow attackers with local access or the ability to trigger the disconnect function to cause system instability, denial of service, or potentially escalate privileges through memory corruption. This could disrupt critical services, especially in sectors like finance, healthcare, and government where Linux is prevalent. Although no exploits are currently known, the kernel-level nature of the flaw means that successful exploitation could compromise system integrity and availability. The vulnerability could also affect IoT devices or industrial control systems running Linux with the vulnerable driver, posing risks to operational technology environments common in European manufacturing and utilities.

European organizations should prioritize updating their Linux kernels to versions where this vulnerability is patched. Since the issue is in the rtl8192e driver, organizations should audit their hardware inventory to identify devices using Realtek rtl8192e wireless adapters. If possible, disabling or removing the vulnerable driver can be a temporary mitigation. For embedded or IoT devices where kernel updates are challenging, vendors should be contacted for firmware updates or patches. Network segmentation and strict access controls can reduce the risk of local exploitation. Additionally, monitoring system logs for unusual disconnect events or crashes related to wireless devices can help detect attempted exploitation. Organizations should also implement robust patch management processes to ensure timely deployment of kernel updates. Finally, consider using alternative wireless hardware or drivers if the rtl8192e driver is not essential.