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.
References
Configurations
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History
07 Nov 2023, 03:20
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Information
Published : 2020-09-23 22:15
Updated : 2024-02-28 18:08
NVD link : CVE-2020-25596
Mitre link : CVE-2020-25596
CVE.ORG link : CVE-2020-25596
JSON object : View
Products Affected
fedoraproject
- fedora
xen
- xen
debian
- debian_linux
opensuse
- leap
CWE
CWE-74
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')