SB2021102041 - Ubuntu update for linux, linux-bluefield, linux-gcp-5.4 and more
Published: October 20, 2021 Updated: October 31, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 6 vulnerabilities.
1) Cryptographic Issues (CVE-ID: CVE-2020-3702)
CWE-ID: CWE-310 - Cryptographic Issues
CVSSv4: 6.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/SI:L/SA:N]
The vulnerability allows a remote attacker to gain access top sensitive information.
The vulnerability exists due to improper input validation in WIFI driver(Krook). A remote attacker can temporary disable WPA2 or the WPA/WPA2 mixed-mode encryption and intercept traffic in clear text.
2) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2021-3732)
CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to gain access to sensitive information.
The vulnerability exists in the way the user mounts the TmpFS filesystem with OverlayFS. A local user can gain access to hidden files that should not be accessible.
3) Incorrect permission assignment for critical resource (CVE-ID: CVE-2021-38198)
CWE-ID: CWE-732 - Incorrect Permission Assignment for Critical Resource
CVSSv4: 6.8 [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]
The vulnerability allows a local user to perform a denial of service attack.
The vulnerability exists due to arch/x86/kvm/mmu/paging_tmpl.h incorrectly computes the access permissions of a shadow page. A local user can trigger an error to perform a denial of service attack.
4) Access of uninitialized pointer (CVE-ID: CVE-2021-38205)
CWE-ID: CWE-824 - Access of Uninitialized Pointer
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to manipulate data.
drivers/net/ethernet/xilinx/xilinx_emaclite.c in the Linux kernel before 5.13.3 makes it easier for attackers to defeat an ASLR protection mechanism because it prints a kernel pointer (i.e., the real IOMEM pointer).
5) Race condition (CVE-ID: CVE-2021-40490)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 8.5 [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]
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition in ext4_write_inline_data_end in fs/ext4/inline.c in the ext4 subsystem in the Linux kernel. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.
6) Out-of-bounds write (CVE-ID: CVE-2021-42008)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error in the decode_data() function in drivers/net/hamradio/6pack.c in the Linux kernel. A local user can send input from a process that has the CAP_NET_ADMIN capability and escalate privileges on the system.
Remediation
Install update from vendor's website.