CVE-2020-29479
Published: 15 December 2020
An issue was discovered in Xen through 4.14.x. In the Ocaml xenstored implementation, the internal representation of the tree has special cases for the root node, because this node has no parent. Unfortunately, permissions were not checked for certain operations on the root node. Unprivileged guests can get and modify permissions, list, and delete the root node. (Deleting the whole xenstore tree is a host-wide denial of service.) Achieving xenstore write access is also possible. All systems using oxenstored are vulnerable. Building and using oxenstored is the default in the upstream Xen distribution, if the Ocaml compiler is available. Systems using C xenstored are not vulnerable.
Notes
Author | Note |
---|---|
mdeslaur | hypervisor packages are in universe. For issues in the hypervisor, add appropriate tags to each section, ex: Tags_xen: universe-binary |
Priority
Status
Package | Release | Status |
---|---|---|
xen Launchpad, Ubuntu, Debian |
trusty |
Does not exist
|
upstream |
Needs triage
|
|
bionic |
Needed
|
|
focal |
Needed
|
|
groovy |
Ignored
(end of life)
|
|
jammy |
Not vulnerable
(4.11.4+57-g41a822c392-2)
|
|
xenial |
Needed
|
|
impish |
Ignored
(end of life)
|
|
hirsute |
Ignored
(end of life)
|
|
kinetic |
Not vulnerable
(4.11.4+57-g41a822c392-2)
|
|
lunar |
Not vulnerable
(4.11.4+57-g41a822c392-2)
|
|
mantic |
Not vulnerable
(4.11.4+57-g41a822c392-2)
|
|
Binaries built from this source package are in Universe and so are supported by the community. |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 8.8 |
Attack vector | Local |
Attack complexity | Low |
Privileges required | Low |
User interaction | None |
Scope | Changed |
Confidentiality | High |
Integrity impact | High |
Availability impact | High |
Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |