{"id":"ALPINE-CVE-2020-11739","details":"An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service or possibly gain privileges because of missing memory barriers in read-write unlock paths. The read-write unlock paths don't contain a memory barrier. On Arm, this means a processor is allowed to re-order the memory access with the preceding ones. In other words, the unlock may be seen by another processor before all the memory accesses within the \"critical\" section. As a consequence, it may be possible to have a writer executing a critical section at the same time as readers or another writer. In other words, many of the assumptions (e.g., a variable cannot be modified after a check) in the critical sections are not safe anymore. The read-write locks are used in hypercalls (such as grant-table ones), so a malicious guest could exploit the race. For instance, there is a small window where Xen can leak memory if XENMAPSPACE_grant_table is used concurrently. A malicious guest may be able to leak memory, or cause a hypervisor crash resulting in a Denial of Service (DoS). Information leak and privilege escalation cannot be excluded.","modified":"2026-08-20T10:18:02.544238312Z","published":"2020-04-14T13:15:12.703Z","upstream":["CVE-2020-11739"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2020-11739"}],"affected":[{"package":{"name":"xen","ecosystem":"Alpine:v3.10","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.12.2-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.11","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.12","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.13","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.14","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.15","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.16","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.17","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.18","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.19","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.20","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json"}},{"package":{"name":"xen","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/xen?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.13.0-r3"}]}]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