SB2020051289 - Red Hat Enterprise Linux 8 update for kernel
Published: May 12, 2020
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) NULL pointer dereference (CVE-ID: CVE-2020-10711)
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.
2) Race condition (CVE-ID: CVE-2020-11884)
The vulnerability allows a local authenticated user to execute arbitrary code.
In the Linux kernel through 5.6.7 on the s390 platform, code execution may occur because of a race condition, as demonstrated by code in enable_sacf_uaccess in arch/s390/lib/uaccess.c that fails to protect against a concurrent page table upgrade, aka CID-3f777e19d171. A crash could also occur.
3) Information disclosure (CVE-ID: CVE-2020-2732)
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.
Remediation
Install update from vendor's website.