CVE-2018-15470: Xen

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

An issue was discovered in Xen through 4.11.x. The logic in oxenstored for handling writes depended on the order of evaluation of expressions making up a tuple. As indicated in section 7.7.3 "Operations on data structures" of the OCaml manual, the order of evaluation of subexpressions is not specified. In practice, different implementations behave differently. Thus, oxenstored may not enforce the configured quota-maxentity. This allows a malicious or buggy guest to write as many xenstore entries as it wishes, causing unbounded memory usage in oxenstored. This can lead to a system-wide DoS.

Affected products

• Xen Xen: up to and including 4.11.0

Published 2018-08-17. Last modified 2026-06-17.