CVE-2020-29481

HIGHCVSS 8.8/10EPSS 0.35%

Last modified

CVE-2020-29481 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. An issue was discovered in Xen through 4.14.x. Access rights of Xenstore nodes are per domid. EPSS estimates a 0.35% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
8.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS Probability
0.35%

26.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
XenXen<= 4.14.0
DebianDebian Linux10.0
FedoraprojectFedora32
FedoraprojectFedora33

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is 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.
How severe is CVE-2020-29481?
CVE-2020-29481 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.35% probability of exploitation in the next 30 days.
How do I fix CVE-2020-29481?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-29481?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST