Vulnerability · Published Jul 7, 2020 · Assigned by mitre
CVE-2020-15563
Medium 6.5
In plain English
A medium-severity security flaw in the xen package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | xen | 4.13.1-r4 | ALPINE-CVE-2020-15563 |
| Alpine:v3.21 | xen | 4.13.1-r4 | ALPINE-CVE-2020-15563 |
| Alpine:v3.22 | xen | 4.13.1-r4 | ALPINE-CVE-2020-15563 |
| Alpine:v3.23 | xen | 4.13.1-r4 | ALPINE-CVE-2020-15563 |
| Alpine:v3.24 | xen | 4.13.1-r4 | ALPINE-CVE-2020-15563 |
| Debian:12 | xen | 4.11.4+24-gddaaccbbab-1 | DEBIAN-CVE-2020-15563 |
| Debian:13 | xen | 4.11.4+24-gddaaccbbab-1 | DEBIAN-CVE-2020-15563 |
| Debian:14 | xen | 4.11.4+24-gddaaccbbab-1 | DEBIAN-CVE-2020-15563 |
Affected products (as reported)
References
- http://xenbits.xen.org/xsa/advisory-319.html x_refsource_MISC
- [oss-security] 20200707 Xen Security Advisory 319 v3 (CVE-2020-15563) - inverted code paths in x86 dirty VRAM tracking mailing-list, x_refsource_MLIST
- DSA-4723 vendor-advisory, x_refsource_DEBIAN
- openSUSE-SU-2020:0965 vendor-advisory, x_refsource_SUSE
- FEDORA-2020-fbc13516af vendor-advisory, x_refsource_FEDORA
- openSUSE-SU-2020:0985 vendor-advisory, x_refsource_SUSE
- FEDORA-2020-76cf2b0f0a vendor-advisory, x_refsource_FEDORA
- GLSA-202007-02 vendor-advisory, x_refsource_GENTOO