CVE-2020-15563
Published: 7 July 2020
An issue was discovered in Xen through 4.13.x, allowing x86 HVM guest OS users to cause a hypervisor crash. An inverted conditional in x86 HVM guests' dirty video RAM tracking code allows such guests to make Xen de-reference a pointer guaranteed to point at unmapped space. A malicious or buggy HVM guest may cause the hypervisor to crash, resulting in Denial of Service (DoS) affecting the entire host. Xen versions from 4.8 onwards are affected. Xen versions 4.7 and earlier are not affected. Only x86 systems are affected. Arm systems are not affected. Only x86 HVM guests using shadow paging can leverage the vulnerability. In addition, there needs to be an entity actively monitoring a guest's video frame buffer (typically for display purposes) in order for such a guest to be able to leverage the vulnerability. x86 PV guests, as well as x86 HVM guests using hardware assisted paging (HAP), cannot leverage the vulnerability.
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 |
bionic |
Not vulnerable
(code not present)
|
| eoan |
Ignored
(reached end-of-life)
|
|
| focal |
Released
(4.11.3+24-g14b62ab3e5-1ubuntu2.3)
|
|
| groovy |
Not vulnerable
(4.11.4+24-gddaaccbbab-1ubuntu2)
|
|
| hirsute |
Not vulnerable
(4.11.4+24-gddaaccbbab-1ubuntu2)
|
|
| impish |
Not vulnerable
(4.11.4+24-gddaaccbbab-1ubuntu2)
|
|
| jammy |
Not vulnerable
(4.11.4+24-gddaaccbbab-1ubuntu2)
|
|
| kinetic |
Not vulnerable
(4.11.4+24-gddaaccbbab-1ubuntu2)
|
|
| precise |
Does not exist
|
|
| trusty |
Does not exist
|
|
| upstream |
Needs triage
|
|
| xenial |
Not vulnerable
(code not present)
|
|
| Binaries built from this source package are in Universe and so are supported by the community. | ||
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.5 |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Changed |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H |