SB2020071724 - Amazon Linux AMI update for kernel
Published: July 17, 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) Use-after-free (CVE-ID: CVE-2020-12657)
The vulnerability allows a local user to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in "block/bfq-iosched.c" file related to "bfq_idle_slice_timer_body". A local user can execute arbitrary code on the target system.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
3) Integer overflow (CVE-ID: CVE-2020-12826)
The vulnerability allows a local user to execute arbitrary code on the target system.
The vulnerability exists due to integer overflow in "exec_id" in "include/linux/sched.h". A local user can pass specially crafted data to the application, trigger integer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Remediation
Install update from vendor's website.