CVE-2024-53179 is a high-severity use-after-free (UAF) vulnerability identified in the Linux kernel's SMB client implementation. The flaw arises in the handling of the signing key within the SMB2.1+ protocol mounts, specifically related to the @ses->auth_key.response object. The vulnerability is triggered due to a race condition between concurrent tasks during the CIFS (Common Internet File System) mount process and SMB2 request handling. Task A executes functions related to mounting and session setup (cifs_mount, dfs_mount_share, get_session, cifs_mount_get_session, cifs_get_smb_ses, cifs_setup_session), while Task B concurrently processes SMB2 requests (cifs_send_recv, compound_send_recv, smb2_setup_request, smb2_calc_signature, crypto_shash_setkey). The race condition leads to a use-after-free scenario where the signing key is accessed after it has been freed, potentially causing memory corruption. The fix involves validating the session status (@ses->ses_status) under a session lock (@ses->ses_lock) to ensure the signing key is only accessed when the session is in a valid state (SES_GOOD or SES_EXITING). This prevents accessing freed memory by confirming the session is not in an invalid or terminated state. The vulnerability is tracked under CWE-416 (Use After Free) and has a CVSS v3.1 score of 7.8, indicating high severity. Exploitation requires local access with low privileges and no user interaction, but the impact on confidentiality, integrity, and availability is high. No known exploits are currently reported in the wild. The vulnerability affects specific Linux kernel versions identified by commit hashes, and the patch is integrated into the kernel source to prevent exploitation.

For European organizations, this vulnerability poses a significant risk, especially for those relying on Linux servers or systems that utilize SMB2.1+ protocol mounts for file sharing and network storage. Exploitation could lead to unauthorized access or manipulation of sensitive data due to compromised confidentiality and integrity, as well as potential denial of service from system crashes or memory corruption. Organizations in sectors such as finance, government, healthcare, and critical infrastructure that depend heavily on Linux-based SMB clients are particularly vulnerable. The use-after-free flaw could be leveraged by attackers with local access to escalate privileges or disrupt services, impacting business continuity and data protection compliance under regulations like GDPR. Given the widespread use of Linux in European data centers and enterprise environments, the vulnerability could affect a broad range of systems if not promptly mitigated.

European organizations should prioritize applying the official Linux kernel patches that address CVE-2024-53179 as soon as they are available. Beyond patching, administrators should audit and restrict local access to systems running vulnerable Linux kernel versions to minimize the risk of exploitation. Implementing strict access controls and monitoring for unusual SMB client activity can help detect attempts to exploit this vulnerability. Network segmentation to isolate SMB traffic and limiting SMB protocol usage to trusted environments reduce exposure. Additionally, organizations should review their SMB mount configurations to ensure they do not unnecessarily use SMB2.1+ signing mounts unless required. Employing kernel hardening techniques such as memory protection features (e.g., KASLR, SMEP, SMAP) can further mitigate exploitation risks. Regular vulnerability scanning and compliance checks should include verification of kernel versions and applied patches related to this issue.