SB2022010637 - Ubuntu update for linux

Description

This security bulletin contains information about 7 vulnerabilities.

1) Protection Mechanism Failure (CVE-ID: CVE-2020-26541)

CWE-ID: CWE-693 - Protection Mechanism Failure

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 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.

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) Unchecked Return Value (CVE-ID: CVE-2021-43056)

CWE-ID: CWE-252 - Unchecked Return Value

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 attack.

The vulnerability exists due to an arch/powerpc/kvm/book3s_hv_rmhandlers.S implementation error when handling SRR1 register values. A local user can perform a denial of service attack, when the host is running on Power8.

7) 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.

References

• https://ubuntu.com/security/notices/USN-5210-1