Rapid7 Vulnerability & Exploit Database

SUSE: CVE-2020-25596: SUSE Linux Security Advisory

Back to Search

SUSE: CVE-2020-25596: SUSE Linux Security Advisory

Severity
2
CVSS
(AV:L/AC:L/Au:N/C:N/I:N/A:P)
Published
09/23/2020
Created
02/09/2021
Added
02/07/2021
Modified
10/22/2021

Description

An issue was discovered in Xen through 4.14.x. x86 PV guest kernels can experience denial of service via SYSENTER. The SYSENTER instruction leaves various state sanitization activities to software. One of Xen's sanitization paths injects a #GP fault, and incorrectly delivers it twice to the guest. This causes the guest kernel to observe a kernel-privilege #GP fault (typically fatal) rather than a user-privilege #GP fault (usually converted into SIGSEGV/etc.). Malicious or buggy userspace can crash the guest kernel, resulting in a VM Denial of Service. All versions of Xen from 3.2 onwards are vulnerable. Only x86 systems are vulnerable. ARM platforms are not vulnerable. Only x86 systems that support the SYSENTER instruction in 64bit mode are vulnerable. This is believed to be Intel, Centaur, and Shanghai CPUs. AMD and Hygon CPUs are not believed to be vulnerable. Only x86 PV guests can exploit the vulnerability. x86 PVH / HVM guests cannot exploit the vulnerability.

Solution(s)

  • suse-upgrade-xen
  • suse-upgrade-xen-devel
  • suse-upgrade-xen-doc-html
  • suse-upgrade-xen-kmp-default
  • suse-upgrade-xen-kmp-pae
  • suse-upgrade-xen-libs
  • suse-upgrade-xen-libs-32bit
  • suse-upgrade-xen-tools
  • suse-upgrade-xen-tools-domu
  • suse-upgrade-xen-tools-xendomains-wait-disk

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;