SB2020051520 - Red Hat Enterprise Linux 8 update for kernel-rt
Published: May 15, 2020 Updated: May 22, 2020
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Information disclosure (CVE-ID: CVE-2020-2732)
CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor
CVSSv4: 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/E:U/U:Clear
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.
2) NULL pointer dereference (CVE-ID: CVE-2020-10711)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in the Linux kernel's SELinux subsystem when importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated.
A remote attacker can send specially crafted packets the affected system, trigger a NULL pointer dereference error and crash the Linux kernel.
Remediation
Install update from vendor's website.