USN-6777-4: Linux kernel (HWE) vulnerabilities

In a recent security update referenced as USN-6777-4, multiple critical vulnerabilities were identified and patched within the Linux kernel. These vulnerabilities span various kernel subsystems and pose serious security risks which, if exploited, could allow attackers to compromise the system, cause denial of services, or gain unauthorized access.

One of the more critical vulnerabilities identified is CVE-2023-47233, which impacts the Broadcom FullMAC WLAN driver. This particular issue involves a race condition during device removal that could lead to a use-after-free vulnerability. Such a vulnerability could be exploited by a physically proximate attacker to cause a system crash, which under certain conditions, could be leveraged for more malicious outcomes.

Additionally, a comprehensive range of issues in other subsystems has been addressed. These include the block layer subsystem, the Ext4, JFS, and NILFS2 file systems, the Ceph distributed file system, the Bluetooth, NFC, MAC80211, and both IPv4 and IPv6 networking subsystems, among others. Each of these patches not only mitigates risks associated with system crashes but also addresses potential pathways that attackers could exploit to take control of a system or escalate their privileges once inside.

The patch details regarding CVE-2023-52439 within the Userspace I/O drivers also reveal extensive risks, involving a corrected use-after-free in uio_open. This specific vulnerability highlighted a significant flaw where an attacker could execute unintended actions by manipulating the memory usage patterns of the driver after it had been freed, potentially leading to arbitrary code execution or information leakage.

The fixes for these vulnerabilities encompass updates across multiple kernel versions, ensuring that systems operating on various iterations of the Linux kernel remain secured against these identified threats. It is crucial for system administrators and users to apply these security updates promptly to mitigate any potential threat effectively.

For more detailed information on these vulnerabilities and to ensure your system is up-to-date with the latest security measures, please visit Staying informed and proactive in applying security patches is essential in maintaining the integrity and security of your systems in the ever-evolving landscape of cybersecurity threats.