Synopsis
The remote Virtuozzo host is missing a security update.
Description
According to the version of the vzkernel package and the readykernel-patch installed, the Virtuozzo installation on the remote host is affected by the following vulnerabilities :
- A use-after-free vulnerability was found in the way KVM implements its device control API. When a device is created via kvm_ioctl_create_device(), it holds a reference to a VM object. This reference is transferred to file descriptor table of the caller. If such file descriptor was closed, reference count to the VM object could become zero, which could lead to a use-after-free issue. A user/process could use this flaw to crash the guest VM resulting in a denial of service or, potentially, gain privileged access to a system.
- A use-after-free vulnerability was found in the way KVM emulates a preemption timer for L2 guests when nested virtualization is enabled. A guest user/process could use this flaw to crash the host kernel resulting in a denial of service or, potentially, gain privileged access to a system.
- It was discovered that a certain sequence of operations related to IPv4 routing could trigger a kernel memory leak. An attacker could potentially exploit that from a container to cause a denial of service.
Note that Tenable Network Security has extracted the preceding description block directly from the Virtuozzo security advisory.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
Solution
Update the readykernel patch.