Virtuozzo 7 : readykernel-patch (VZA-2017-098)
High Nessus Plugin ID 104132
SynopsisThe remote Virtuozzo host is missing a security update.
DescriptionAccording 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 :
- Linux kernel built with the KVM virtualisation support (CONFIG_KVM), with nested virtualisation (nVMX) feature enabled (nested=1), is vulnerable to a stack buffer overflow issue. It could occur while traversing guest pagetable entries to resolve guest virtual address. A guest system could use this flaw to crash the host kernel resulting in DoS, or potentially execute arbitrary code on the host.
- A flaw was found in the Linux networking subsystem where a local attacker with CAP_NET_ADMIN capabilities could cause an out-of-bounds memory access by creating a smaller-than-expected ICMP header and sending to its destination via sendto().
- It was found that in the Linux kernel through v4.14-rc5, bio_map_user_iov() and bio_unmap_user() in 'block/bio.c' do unbalanced pages refcounting if IO vector has small consecutive buffers belonging to the same page. bio_add_pc_page() merges them into one, but the page reference is never dropped, causing a memory leak and possible system lockup due to out-of-memory condition.
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.
SolutionUpdate the readykernel patch.