SB2021072291 - Debian update for linux
Published: July 22, 2021 Updated: August 9, 2022
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2020-36311)
The vulnerability allows a local user to perform a denial of service attack.
The vulnerability exists due to an error in arch/x86/kvm/svm/sev.c in Linux kernel, which allows soft lockup by triggering destruction of a large SEV VM (which requires unregistering many encrypted regions).
2) Race condition (CVE-ID: CVE-2021-3609)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition in the CAN BCM networking protocol (net/can/bcm.c) in the Linux kernel ranging from version 2.6.25 to mainline 5.13-rc6. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.
3) 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.
4) Use of uninitialized resource (CVE-ID: CVE-2021-34693)
The vulnerability allows a local user to gain access to sensitive information.
The vulnerability exists due to net/can/bcm.c in the Linux kernel through 5.12.10 allows local users to obtain sensitive information from kernel stack memory because parts of a data structure are uninitialized.
Remediation
Install update from vendor's website.