PT-2020-6765 · Xen · Xen
Andrew Cooper
+1
·
Published
2020-12-15
·
Updated
2021-03-16
·
CVE-2020-29482
CVSS v3.1
6.0
Medium
| Vector | AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Xen versions through 4.14.x
Description
An issue was discovered in Xen where a guest may access xenstore paths via absolute paths containing a full pathname, or via a relative path, which implicitly includes
/local/domain/$DOMID for their own domain id. Management tools must access paths in guests' namespaces, necessarily using absolute paths. oxenstored imposes a pathname limit that is applied solely to the relative or absolute path specified by the client. Therefore, a guest can create paths in its own namespace which are too long for management tools to access. Depending on the toolstack in use, a malicious guest administrator might cause some management tools and debugging operations to fail. For example, a guest administrator can cause "xenstore-ls -r" to fail. However, a guest administrator cannot prevent the host administrator from tearing down the domain. All systems using oxenstored are vulnerable.Recommendations
As a temporary workaround, consider restricting access to the
xenstore paths to minimize the risk of exploitation.
To resolve the issue, ensure that the Ocaml compiler is not available or switch to using C xenstored, as systems using C xenstored are not vulnerable.
At the moment, there is no information about a newer version that contains a fix for this vulnerability.Untrusted Search Path
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Weakness Enumeration
Related Identifiers
Affected Products
Xen