CVE-2022-49541 is a vulnerability identified in the Linux kernel's CIFS (Common Internet File System) client implementation. The issue involves a potential double free condition that can occur during a failed mount operation. Specifically, when the CIFS client attempts to mount a remote share and the mount process fails, improper handling of memory deallocation can lead to the same memory being freed twice. This double free vulnerability can cause undefined behavior, including kernel crashes (denial of service) or potentially enable an attacker to execute arbitrary code with kernel privileges if exploited successfully. The vulnerability arises from a flaw in the error handling path of the CIFS mount code, where pointers are freed without proper nullification or checks, leading to memory corruption. The vulnerability was reported and fixed in the Linux kernel, with the patch addressing the double free condition to ensure safe memory management during mount failures. There are no known exploits in the wild at the time of publication, and the vulnerability does not have an assigned CVSS score. The affected versions are identified by specific commit hashes, indicating the vulnerability is present in certain kernel builds prior to the patch. The CIFS client is widely used in Linux environments to mount SMB shares, making this vulnerability relevant for systems that rely on network file sharing with Windows or Samba servers.

For European organizations, the impact of CVE-2022-49541 can be significant depending on their reliance on CIFS mounts for accessing network file shares. Exploitation of this vulnerability could lead to kernel crashes, resulting in denial of service conditions on critical servers or endpoints. In more severe cases, if an attacker can leverage the double free to execute arbitrary code in kernel space, it could lead to full system compromise, allowing attackers to bypass security controls, escalate privileges, and move laterally within networks. Organizations using Linux servers as file servers, application hosts, or in cloud environments that mount SMB shares are particularly at risk. Disruption of file sharing services can impact business continuity, especially in sectors like finance, manufacturing, and public services where file access is critical. Additionally, the potential for privilege escalation raises concerns for data confidentiality and integrity. Although no exploits are currently known, the presence of this vulnerability in widely deployed Linux kernels means that European organizations should proactively address it to prevent future exploitation.

To mitigate CVE-2022-49541, European organizations should: 1) Apply the latest Linux kernel patches that address the double free vulnerability in the CIFS client code as soon as they become available from their Linux distribution vendors. 2) Review and update all systems that mount SMB/CIFS shares to ensure they are running patched kernel versions. 3) Implement strict network segmentation and access controls to limit exposure of CIFS mounts to untrusted or external networks, reducing the attack surface. 4) Monitor system logs and kernel messages for unusual mount failures or crashes that could indicate exploitation attempts. 5) Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR) and Control Flow Integrity (CFI) to make exploitation more difficult. 6) Conduct regular vulnerability assessments and penetration testing focused on network file sharing services to detect potential weaknesses. 7) Educate system administrators on the importance of timely patching and secure configuration of CIFS mounts.