Vigil@nce: Linux kernel, privilege elevation via VMI
October 2008 by Vigil@nce
A local attacker in a virtual machine can create a denial of
service or elevate his privileges.
– Gravity: 2/4
– Consequences: privileged access/rights, denial of service of
computer
– Provenance: user account
– Means of attack: no proof of concept, no attack
– Ability of attacker: expert (4/4)
– Confidence: confirmed by the editor (5/5)
– Diffusion of the vulnerable configuration: high (3/3)
– Creation date: 06/10/2008
IMPACTED PRODUCTS
– Linux kernel
DESCRIPTION
The VMI (Virtual Machine Interface) is used for communication
between the guest system and the hypervisor.
The LDT (Local Descriptor Table) contains information about memory
segments of the process. The IDT (Interrupt Descriptor Table) is
used to manage interruptions.
The vmi_write_ldt_entry() function of the arch/x86/kernel/vmi_32.c
file uses write_idt_entry() instead of write_ldt_entry(), which
corrupts the IDT.
A local attacker, in a guest system, can thus create a denial of
service and eventually execute code.
CHARACTERISTICS
– Identifiers: BID-31565, CVE-2008-4410, VIGILANCE-VUL-8149
– Url: http://vigilance.aql.fr/vulnerability/8149