CVE-2020-29571
Published: 15 December 2020
An issue was discovered in Xen through 4.14.x. A bounds check common to most operation time functions specific to FIFO event channels depends on the CPU observing consistent state. While the producer side uses appropriately ordered writes, the consumer side isn't protected against re-ordered reads, and may hence end up de-referencing a NULL pointer. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. Only Arm systems may be vulnerable. Whether a system is vulnerable depends on the specific CPU. x86 systems 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 |
bionic |
Needed
|
| focal |
Needed
|
|
| groovy |
Ignored
(end of life)
|
|
| hirsute |
Ignored
(end of life)
|
|
| impish |
Ignored
(end of life)
|
|
| jammy |
Not vulnerable
(4.11.4+57-g41a822c392-2)
|
|
| 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)
|
|
| trusty |
Does not exist
|
|
| upstream |
Needs triage
|
|
| xenial |
Needed
|
|
| Binaries built from this source package are in Universe and so are supported by the community. | ||
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.2 |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |