CVE-2020-29479
An issue was discovered in Xen through 4.14.x. In the Ocaml xenstored implementation, the...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
8.8
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.
- Record
CVE-2020-29479- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - CVSS 2.0
- 7.2 High
AV:L/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-862
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2020-29479- Updated
- 2026-11-02
EUVDEUVD-2020-21847 No score
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.
- Record
EUVD-2020-21847- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-mrwx-r54g-7x9f
8.8
An issue was discovered in Xen through 4.14.x. In the Ocaml xenstored implementation, the...
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.
- Record
GHSA-mrwx-r54g-7x9f- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-732, CWE-862
- Updated
- 2026-11-02
OSVALPINE-CVE-2020-29479
8.8
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.
- Record
ALPINE-CVE-2020-29479- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSV
8.8
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.
- Record
CVE-2020-29479- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2020-29479
8.8
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.
- Record
DEBIAN-CVE-2020-29479- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-29479
8.8
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.
- Record
UBUNTU-CVE-2020-29479- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
xenAlpine:v3.11 |
before 4.13.2-r3 | 4.13.2-r3 |
xenAlpine:v3.12 |
before 4.13.2-r3 | 4.13.2-r3 |
xenAlpine:v3.13 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.14 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.15 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.16 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.17 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.18 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.19 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.20 |
before 4.14.1-r0 | 4.14.1-r0 |
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| Package | Affected | Fixed |
|---|---|---|
xenAlpine:v3.21 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.22 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.23 |
before 4.14.1-r0 | 4.14.1-r0 |
xenAlpine:v3.24 |
before 4.14.1-r0 | 4.14.1-r0 |
xenDebian:12 |
before 4.14.0+88-g1d1d1f5391-1 | 4.14.0+88-g1d1d1f5391-1 |
xenDebian:13 |
before 4.14.0+88-g1d1d1f5391-1 | 4.14.0+88-g1d1d1f5391-1 |
xenDebian:14 |
before 4.14.0+88-g1d1d1f5391-1 | 4.14.0+88-g1d1d1f5391-1 |
xenDebian:10 From an advisory covering 11 CVEs |
before 4.11.4+57-g41a822c392-2, plus listed versions 4.11.1+92-g6c33308a8d-24.11.3+24-g14b62ab3e5-14.11.3+24-g14b62ab3e5-1~deb10u14.11.4+24-gddaaccbbab-14.11.4+24-gddaaccbbab-1~deb10u14.11.4+37-g3263f257ca-14.11.4+57-g41a822c392-14.11.4-1 |
4.11.4+57-g41a822c392-2 |
xenUbuntu:16.04:LTS |
All versions, plus listed versions 4.5.1-0ubuntu14.5.1-0ubuntu24.6.0-1ubuntu14.6.0-1ubuntu24.6.0-1ubuntu4 Show 7 moreShow less4.6.0-1ubuntu4.14.6.0-1ubuntu4.24.6.0-1ubuntu4.34.6.5-0ubuntu14.6.5-0ubuntu1.14.6.5-0ubuntu1.24.6.5-0ubuntu1.4 |
None known |
xenUbuntu:18.04:LTS |
All versions, plus listed versions 4.9.0-0ubuntu34.9.0-0ubuntu44.9.2-0ubuntu1 |
None known |
xenUbuntu:20.04:LTS |
All versions, plus listed versions 4.9.2-0ubuntu24.9.2-0ubuntu64.9.2-0ubuntu74.11.3+24-g14b62ab3e5-1ubuntu14.11.3+24-g14b62ab3e5-1ubuntu24.11.3+24-g14b62ab3e5-1ubuntu2.24.11.3+24-g14b62ab3e5-1ubuntu2.3 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-29479 is a high vulnerability (CVSS 8.8) in Xen, published December 15, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 23rd percentile. Fixed in xen 4.13.2-r3.
References
xenbits.xenproject.org/xsa/advisory-353.html
debian.org/security/2020/dsa-4812
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA
security.gentoo.org/glsa/202107-30
nvd.nist.gov/vuln/detail/CVE-2020-29479
Show 9 moreShow less
lists.fedoraproject.org/archives/list/[email protected]/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA
lists.fedoraproject.org/archives/list/[email protected]/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI
github.com/advisories/GHSA-mrwx-r54g-7x9f
security.alpinelinux.org/vuln/CVE-2020-29479
security-tracker.debian.org/tracker/CVE-2020-29479
ubuntu.com/security/CVE-2020-29479
xenbits.xen.org/xsa/advisory-353.html
xenbits.xen.org/xsa/xsa353.patch
cve.org/CVERecord?id=CVE-2020-29479