CVE-2020-15564 Denial of service in n/a
A malicious guest administrator can crash the Xen hypervisor on Arm systems by passing a misaligned address to a specific hypercall, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-15564?
CVE-2020-15564 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 7 Jul 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-119
Which versions are affected by CVE-2020-15564?
It affects 3 products.
Products include Debian Debian Linux, Fedoraproject Fedora, Xen Xen.
How do I fix CVE-2020-15564?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-15564 being exploited?
There is no known exploitation of CVE-2020-15564 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALPINE-CVE-2020-15564, DEBIAN-CVE-2020-15564, GHSA-m5jw-hjp2-vr52, UBUNTU-CVE-2020-15564.