SB2021072251 - Red Hat Enterprise Linux 8.2 update for kernel
Published: July 22, 2021 Updated: August 9, 2022
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 secuirty vulnerabilities.
1) Memory leak (CVE-ID: CVE-2020-25704)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to memory leak within the Linux kernel performance monitoring subsystem when using PERF_EVENT_IOC_SET_FILTER. A local user could use this flaw to starve the resources causing denial of service.
2) Protection Mechanism Failure (CVE-ID: CVE-2020-26541)
The vulnerability allows a local user to escalate privileges on the system.
The Linux kernel through 5.8.13 does not properly enforce the Secure
Boot Forbidden Signature Database (aka dbx) protection mechanism. This
affects certs/blacklist.c and certs/system_keyring.c. A local user can escalate privileges on the system.
3) Improper Initialization (CVE-ID: CVE-2020-35508)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to improper initialization of the process id in the Linux kernel child/parent process identification handling while filtering signal handlers. A local user can run a specially crafted application to bypass checks to send any signal to a privileged process.
4) Use-after-free (CVE-ID: CVE-2021-33034)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error in net/bluetooth/hci_event.c when destroying an hci_chan. A local user can escalate privileges on the system.
5) Integer overflow (CVE-ID: CVE-2021-33909)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to integer overflow during size_t-to-int conversion when creating, mounting, and deleting a deep directory structure whose total path length exceeds 1GB. An unprivileged local user can write up to 10-byte string to an offset of exactly -2GB-10B below the beginning of a vmalloc()ated kernel buffer.
Successful exploitation of vulnerability may allow an attacker to exploit the our-of-bounds write vulnerability to execute arbitrary code with root privileges.
Remediation
Install update from vendor's website.