CVE-2023-52530 is a vulnerability identified in the Linux kernel's wireless networking subsystem, specifically within the mac80211 component responsible for managing Wi-Fi operations. The flaw involves a potential use-after-free condition triggered during the handling of GTK (Group Temporal Key) rekeying, a process used to update encryption keys for Wi-Fi security. The vulnerability arises when the function ieee80211_key_link() is called by ieee80211_gtk_rekey_add() but returns 0 due to KRACK (Key Reinstallation Attacks) protection mechanisms that prevent identical key reinstallations. Despite this, ieee80211_gtk_rekey_add() erroneously returns a pointer to the key, which may have already been freed, leading to a use-after-free scenario. This can cause undefined behavior including memory corruption or crashes. The issue is typically encountered only in the context of iwlwifi drivers during WoWLAN (Wake on Wireless LAN) rekey offload operations, which themselves have KRACK protections, reducing the likelihood of exploitation. The fix involves modifying ieee80211_gtk_rekey_add() to return an error code when ieee80211_key_link() returns 0, converting this error to success only at the cfg80211 boundary, thus preserving expected behavior for legitimate callers while preventing misuse by faulty callers. This patch effectively eliminates the use-after-free risk by ensuring that invalid pointers are not returned. No known exploits are currently reported in the wild, and the vulnerability was published on March 2, 2024.

For European organizations, this vulnerability poses a moderate risk primarily to systems running Linux kernels with affected versions and utilizing Wi-Fi networking, especially those employing Intel wireless drivers (iwlwifi) with WoWLAN rekey offload enabled. Exploitation could lead to denial of service through kernel crashes or potentially enable privilege escalation or arbitrary code execution if an attacker can manipulate kernel memory via the use-after-free. This is particularly relevant for enterprises relying on Linux-based infrastructure, including servers, embedded devices, and endpoint systems with wireless connectivity. The impact on confidentiality, integrity, and availability could be significant if exploited, especially in critical infrastructure or environments with sensitive data. However, the exploitation complexity is higher due to the specific conditions required (WoWLAN rekey offload and KRACK protections), and no active exploits have been reported. Nonetheless, the vulnerability underscores the importance of maintaining updated Linux kernels to avoid latent risks in wireless security components.

European organizations should prioritize updating their Linux kernel versions to incorporate the patch that addresses CVE-2023-52530. Specifically, kernel maintainers and system administrators should verify that ieee80211_gtk_rekey_add() behavior aligns with the fix by returning appropriate error codes to prevent use-after-free conditions. For systems using Intel wireless drivers with WoWLAN rekey offload, consider temporarily disabling WoWLAN rekey offload if immediate patching is not feasible, as this reduces the attack surface. Additionally, organizations should audit their wireless configurations to ensure KRACK protections are enabled and functioning correctly. Employing kernel hardening techniques such as memory protection features (e.g., Kernel Address Space Layout Randomization, KASLR) and enabling security modules (e.g., SELinux, AppArmor) can further mitigate exploitation risks. Regular vulnerability scanning and monitoring for unusual kernel behavior or crashes related to wireless operations are recommended to detect potential exploitation attempts early.