CVE-2020-29481

An issue was discovered in Xen through 4.14.x. Access rights of Xenstore
nodes are per domid. Unfortunately, existing granted access rights are not
removed when a domain is being destroyed. This means that a new domain
created with the same domid will inherit the access rights to Xenstore
nodes from the previous domain(s) with the same domid. Because all Xenstore
entries of a guest below /local/domain/<domid> are being deleted by Xen
tools when a guest is destroyed, only Xenstore entries of other guests
still running are affected. For example, a newly created guest domain might
be able to read sensitive information that had belonged to a previously
existing guest domain. Both Xenstore implementations (C and Ocaml) are
vulnerable.

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