Vulnerability in Xen
CVE-2019-19580
An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable promotion and demotion operations, because of an incomplete fix for CVE-2019-18421. XSA-299 addressed several critical issues in restartable PV type change operations. Despite extensive testing and auditing, some corner cases were missed. A malicious PV guest administrator may be able to escalate their privilege to that of the host. All security-supported versions of Xen are vulnerable. Only x86 systems are affected. Arm systems are not affected. Only x86 PV guests can leverage the vulnerability. x86 HVM and PVH guests cannot leverage the vulnerability. Note that these attacks require very precise timing, which may be difficult to exploit in practice.
Vulnerability class: Race Condition
EPSS: 0.012 (64.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Xen
- Fedoraproject Fedora — versions 31
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (Patch, x_refsource_MISC, Vendor Advisory)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
- cve@mitre.org (vendor-advisory, x_refsource_SUSE)
- cve@mitre.org (vendor-advisory, x_refsource_DEBIAN)
- cve@mitre.org (mailing-list, x_refsource_BUGTRAQ)
- cve@mitre.org (vendor-advisory, x_refsource_GENTOO)
Frequently asked questions
- What is CVE-2019-19580?
- CVE-2019-19580 is a medium-severity vulnerability in Xen, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 6.6/10. Published 2019-12-11.
- How severe is CVE-2019-19580?
- Medium severity. CVSS v3 base score is 6.6 out of 10.