Resource management error in Xen - CVE-2019-19581
Published: July 28, 2020
Vulnerability details
The vulnerability allows a remote user to perform a denial of service (DoS) attack.
An issue was discovered in Xen through 4.12.x allowing 32-bit Arm guest OS users to cause a denial of service (out-of-bounds access) because certain bit iteration is mishandled. In a number of places bitmaps are being used by the hypervisor to track certain state. Iteration over all bits involves functions which may misbehave in certain corner cases: On 32-bit Arm accesses to bitmaps with bit a count which is a multiple of 32, an out of bounds access may occur. A malicious guest may cause a hypervisor crash or hang, resulting in a Denial of Service (DoS). All versions of Xen are vulnerable. 32-bit Arm systems are vulnerable. 64-bit Arm systems are not vulnerable.
Affected software
Gentoo Linux
Debian Linux
Opensuse
Fedora
xen (Debian package)
xen
How to mitigate CVE-2019-19581
xen - addressed in versions 4.11.3-2.fc30, 4.12.1-8.fc31
External References
- http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00011.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/34HBFTYNMQMWIO2GGK7DB6KV4M6R5YPV/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/D5R73AYE53QA32KTMHUVKCX6E52CIS43/
- https://seclists.org/bugtraq/2020/Jan/21
- https://security.gentoo.org/glsa/202003-56
- https://www.debian.org/security/2020/dsa-4602
- https://xenbits.xen.org/xsa/advisory-307.html