Buffer overflow in Xen
CVE-2020-15564
An issue was discovered in Xen through 4.13.x, allowing Arm guest OS users to cause a hypervisor crash because of a missing alignment check in VCPUOP_register_vcpu_info. The hypercall VCPUOP_register_vcpu_info is used by a guest to register a shared region with the hypervisor. The region will be mapped into Xen address space so it can be directly accessed. On Arm, the region is accessed with instructions that require a specific alignment. Unfortunately, there is no check that the address provided by the guest will be correctly aligned. As a result, a malicious guest could cause a hypervisor crash by passing a misaligned address. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). All Xen versions are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected.
Vulnerability class: Buffer Overflow
EPSS: 0.004 (32.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.
Affected products
- Xen
- Debian Debian_linux — versions 10.0
- Fedoraproject Fedora — versions 31, 32
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (mailing-list, x_refsource_MLIST, Patch, Mailing List, Third Party Advisory)
- cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
- cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
Frequently asked questions
- What is CVE-2020-15564?
- CVE-2020-15564 is a medium-severity vulnerability in Xen, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 6.5/10. Published 2020-07-07.
- How severe is CVE-2020-15564?
- Medium severity. CVSS v3 base score is 6.5 out of 10.