CVE-2023-3865

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ksmbd: se corrige una lectura fuera de los límite en smb2_write. ksmbd_smb2_check_message no valida hdr->NextCommand. Si ->NextCommand es mayor que Offset + Length de la escritura smb2, se permite una longitud de escritura smb2 sobredimensionada. Esto provoca una lectura fuera de los límite en smb2_write.

This vulnerability allows remote attackers to disclose sensitive information on affected installations of Linux Kernel. Authentication may or may not be required to exploit this vulnerability, depending upon configuration. Furthermore, only systems with ksmbd enabled are vulnerable.
The specific flaw exists within the parsing of smb2_hdr structure. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the kernel.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix out-of-bound read in smb2_write ksmbd_smb2_check_message doesn't validate hdr->NextCommand. If ->NextCommand is bigger than Offset + Length of smb2 write, It will allow oversized smb2 write length. It will cause OOB read in smb2_write.

It was discovered that the IPv6 implementation in the Linux kernel contained a high rate of hash collisions in connection lookup table. A remote attacker could use this to cause a denial of service. Daniël Trujillo, Johannes Wikner, and Kaveh Razavi discovered that some AMD processors utilising speculative execution and branch prediction may allow unauthorised memory reads via a speculative side-channel attack. A local attacker could use this to expose sensitive information, including kernel memory.