virtualization_host

A flaw was found in the Linux 4.x kernel’s implementation of 32-bit syscall interface for bridging. This allowed a privileged user to arbitrarily write to a limited range of kernel memory.

The do_get_mempolicy function in mm/mempolicy.c in the Linux kernel before 4.12.9 allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via crafted system calls.

A flaw was found in the way Samba maps domain users to local users. An authenticated attacker could use this flaw to cause possible privilege escalation.

An out-of-bounds access issue was found in the Linux kernel, all versions through 5.3, in the way Linux kernel’s KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer ‘struct kvm_coalesced_mmio’ object, wherein write indices ‘ring->first’ and ‘ring->last’ value could be supplied by a host user-space process. An unprivileged host user or process with access to ‘/dev/kvm’ device could use this flaw to crash the host kernel, resulting in a denial of service or potentially escalating privileges on the system.

The Samba vfs_fruit module uses extended file attributes (EA, xattr) to provide “…enhanced compatibility with Apple SMB clients and interoperability with a Netatalk 3 AFP fileserver.” Samba versions prior to 4.13.17, 4.14.12 and 4.15.5 with vfs_fruit configured allow out-of-bounds heap read and write via specially crafted extended file attributes. A remote attacker with write access to extended file attributes can execute arbitrary code with the privileges of smbd, typically root.

A use-after-free flaw was found in the Linux kernel’s Bluetooth subsystem in the way user calls connect to the socket and disconnect simultaneously due to a race condition. This flaw allows a user to crash the system or escalate their privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.