Information disclosure in Linux kernel - CVE-2020-2732

Vulnerability identifier: #VU25814

CSH Severity: Low

CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-2732

CWE-ID: CWE-200

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to incomplete implementation of vmx_check_intercept on Intel processors in KVM in Linux kernel, which leads to  I/O or MSR interception bitmaps are not checked. A remote attacker with access to guest operating system (e.g. L2 guest) can trick the L0 hypervisor into accessing sensitive information on the L1 hypervisor.

Linux kernel
Amazon Linux AMI
Arch Linux
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux for ARM 64
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Slackware Linux
Fedora
kernel-rt (Red Hat package)
kernel (Red Hat package)
linux-4.4.217/kernel-generic
linux-4.4.217/kernel-huge
linux-4.4.217/kernel-modules
linux-4.4.217/kernel-headers
kernel

Install updates from vendor's website.

Linux kernel - update to 5.6
kernel-rt (Red Hat package) - addressed in versions 3.10.0-1160.rt56.1131.el7, 4.18.0-193.1.2.rt13.53.el8_2
kernel (Red Hat package) - addressed in versions 3.10.0-1160.el7, 4.18.0-193.1.2.el8_2
linux-4.4.217/kernel-generic - update to 4.4.217
linux-4.4.217/kernel-huge - update to 4.4.217
linux-4.4.217/kernel-modules - update to 4.4.217
linux-4.4.217/kernel-headers - update to 4.4.217_smp
kernel - addressed in versions 5.5.7-100.fc30, 5.5.7-200.fc31

• https://security.archlinux.org/advisory/ASA-202003-6
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.6

• Multiple vulnerabilities in Linux kernel
• Arch Linux update for Linux
• Red Hat Enterprise Linux 8 update for kernel-rt
• Amazon Linux AMI update for kernel
• Red Hat Enterprise Linux 8 update for kernel
• Slackware Linux update for kernel
• Red Hat Enterprise Linux 7 update for kernel-rt
• Red Hat Enterprise Linux 7 update for kernel
• Fedora 31 update for kernel
• Fedora 30 update for kernel