CVE-2020-29479 | Date: (C)2020-12-16 (M)2023-12-22 |
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 and Metrics +CVSS Score and Metrics -CVSS V3 Severity: | CVSS V2 Severity: |
CVSS Score : 8.8 | CVSS Score : 7.2 |
Exploit Score: 2.0 | Exploit Score: 3.9 |
Impact Score: 6.0 | Impact Score: 10.0 |
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CVSS V3 Metrics: | CVSS V2 Metrics: |
Attack Vector: LOCAL | Access Vector: LOCAL |
Attack Complexity: LOW | Access Complexity: LOW |
Privileges Required: LOW | Authentication: NONE |
User Interaction: NONE | Confidentiality: COMPLETE |
Scope: CHANGED | Integrity: COMPLETE |
Confidentiality: HIGH | Availability: COMPLETE |
Integrity: HIGH | |
Availability: HIGH | |
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