ALPINE-CVE-2020-11739
- Source
- https://security.alpinelinux.org/vuln/CVE-2020-11739
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2020-11739.json
- JSON Data
- https://api.osv.dev/v1/vulns/ALPINE-CVE-2020-11739
- Upstream
- Published
- 2020-04-14T13:15:12Z
- Modified
- 2026-08-27T12:17:45Z
- Severity
-
- 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H CVSS Calculator
- Summary
- [none]
- 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.
- References