CVE-2020-29479
At a glance
- Source
- NVD
- EPSS
- EPSS 0.31 % · percentile 24 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- mitre
- NVD status
- Modified
Description
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.
Weaknesses (CWE)
- CWE-862 — Missing Authorization
References
- https://xenbits.xenproject.org/xsa/advisory-353.html
- https://www.debian.org/security/2020/dsa-4812
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/
- https://security.gentoo.org/glsa/202107-30
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H | NVD · nvd@nist.gov (Primary) |
| CVSS 2.0 | HIGH 7.2 | AV:L/AC:L/Au:N/C:C/I:C/A:C | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2020-21847
- GCVE · GCVE-0-2020-29479
CERT-FR advisories
- CERTFR-2020-AVI-825 — Vulnérabilité dans Citrix Hypervisor · cert.ssi.gouv.fr
- CERTFR-2020-AVI-824 — Multiples vulnérabilités dans Xen · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*≤ 4.14.0cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| affected n/a |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |