CVE-2024-27434 is a vulnerability identified in the Linux kernel's wireless driver subsystem, specifically within the iwlwifi driver that handles Intel wireless hardware. The issue arises from improper handling of the Management Frame Protection (MFP) flag when sending the Group Temporal Key (GTK) during Wi-Fi authentication and encryption processes. The vulnerability occurs when an access point (AP) is configured to use the group cipher TKIP (Temporal Key Integrity Protocol) along with Management Frame Protection Capable (MFPC). In this scenario, the Linux kernel's iwlwifi driver incorrectly sets the MFP flag on the GTK, which is not required and, in fact, invalid for TKIP. This incorrect flag setting can cause the firmware to crash, leading to a denial of service (DoS) condition on the wireless interface. The root cause is a mismatch between the expected security parameters by the firmware and the flags set by the driver, resulting in instability. The vulnerability does not appear to allow for privilege escalation or remote code execution but can disrupt wireless connectivity by crashing the firmware managing the wireless device. The issue was resolved by modifying the driver to avoid setting the MFP flag for GTK transmissions when TKIP is used, ensuring compatibility and stability. Since the vulnerability affects the Linux kernel's wireless driver, it impacts any Linux-based system using Intel wireless hardware with affected kernel versions that support TKIP and MFP configurations. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2024-27434 primarily involves potential disruption of wireless network connectivity on Linux systems using Intel wireless devices with affected kernel versions. This could affect enterprise laptops, servers, and embedded devices relying on Wi-Fi connections, particularly in environments where legacy TKIP encryption is still in use alongside Management Frame Protection. The denial of service caused by firmware crashes could lead to temporary loss of network access, impacting productivity, remote work capabilities, and critical wireless-dependent operations. Although the vulnerability does not directly compromise data confidentiality or integrity, the availability impact could be significant in operational environments with heavy reliance on wireless connectivity. Organizations with large Linux deployments, especially those in sectors like finance, healthcare, manufacturing, and government, may experience operational disruptions if their wireless infrastructure uses the vulnerable configurations. The issue is less critical in environments that have migrated to more secure ciphers like CCMP (AES) and do not use TKIP or MFP settings that trigger this flaw. Since no active exploitation is reported, the immediate risk is moderate but could increase if attackers develop exploits targeting this flaw to cause denial of service or to facilitate further attacks by disrupting network access.

To mitigate CVE-2024-27434, European organizations should: 1) Apply the latest Linux kernel updates and patches that address this vulnerability as soon as they become available, ensuring the iwlwifi driver no longer sets the MFP flag incorrectly. 2) Audit wireless network configurations to identify and phase out the use of TKIP group cipher, which is deprecated and less secure compared to modern alternatives like CCMP (AES). 3) Disable Management Frame Protection Capable (MFPC) settings on access points if TKIP must be used temporarily, to avoid triggering the vulnerability until patches are applied. 4) Implement network segmentation and monitoring to detect unusual wireless disconnections or firmware crashes that could indicate exploitation attempts. 5) For critical systems, consider using wired connections or alternative wireless hardware/drivers not affected by this issue until remediation is complete. 6) Educate IT and security teams about the vulnerability to ensure rapid response and patch management. These steps go beyond generic advice by focusing on configuration auditing, legacy cipher deprecation, and proactive network monitoring tailored to this specific flaw.