USN-3651-1: QEMU update

21 May 2018

Side channel execution mitigations were added to QEMU.



  • qemu - Machine emulator and virtualizer


Ken Johnson and Jann Horn independently discovered that microprocessors utilizing
speculative execution of a memory read may allow unauthorized memory reads via
sidechannel attacks. An attacker in the guest could use this to expose sensitive
guest information, including kernel memory. This update allows QEMU to expose new
CPU features added by microcode updates to guests on amd64 and i386.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 18.04
Ubuntu 17.10
Ubuntu 16.04
Ubuntu 14.04

After a standard system update you need to restart all QEMU virtual
machines to make all the necessary changes.