Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Xen | Xen | <= 4.14.0 |
| Debian | Debian Linux | 10.0 |
| Fedoraproject | Fedora | 32 |
Related Weaknesses (CWE)
References
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202107-30Third Party Advisory
- https://www.debian.org/security/2020/dsa-4812Third Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-353.htmlPatchVendor Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202107-30Third Party Advisory
- https://www.debian.org/security/2020/dsa-4812Third Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-353.htmlPatchVendor Advisory
FAQ
What is CVE-2020-29479?
CVE-2020-29479 is a vulnerability with a CVSS score of 8.8 (HIGH). 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. Unfo...
How severe is CVE-2020-29479?
CVE-2020-29479 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-29479?
Check the references section above for vendor advisories and patch information. Affected products include: Xen Xen, Debian Debian Linux, Fedoraproject Fedora.