SB2022010636 - Ubuntu update for linux
Published: January 6, 2022
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 6 vulnerabilities.
1) Improper Initialization (CVE-ID: CVE-2021-20317)
CWE-ID: CWE-665 - Improper Initialization
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to improper initialization the Linux kernel. A corrupted timer tree causes the task wakeup to be missing in the timerqueue_add function in lib/timerqueue.c. A local user can run a specially crafted application to crash the kernel.
2) Race condition (CVE-ID: CVE-2021-20321)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to perform a denial of service (DoS) attacks.
The vulnerability exists due to a race condition when accessing file object in the Linux kernel OverlayFS subsystem. A local user can rename files in specific way with OverlayFS and perform a denial of service (DoS) attack.
3) Use-after-free (CVE-ID: CVE-2021-3760)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error in the NFC stack. A local user can trigger use-after-free error to escalate privileges on the system.
4) Memory leak (CVE-ID: CVE-2021-4002)
CWE-ID: CWE-401 - Missing release of memory after effective lifetime
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to gain access to sensitive information.
The vulnerability exists due memory leak in the Linux kernel's hugetlbfs memory usage. A local user can force the application to leak memory and gain access to sensitive information.
5) Out-of-bounds write (CVE-ID: CVE-2021-41864)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error when processing untrusted input. A local user can gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information.
6) Improper Validation of Array Index (CVE-ID: CVE-2021-43389)
CWE-ID: CWE-129 - Improper Validation of Array Index
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to execute arbitrary code with elevated privileges.
The vulnerability exists due to improper validation of array index in the ISDN CAPI implementation within detach_capi_ctr() function in drivers/isdn/capi/kcapi.c. A local user can send specially crafted data to the system and execute arbitrary code with elevated privileges.
Remediation
Install update from vendor's website.