SB2021041393 - Ubuntu update for linux

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Main Vulnerability Database SB2021041393

SB2021041393 - Ubuntu update for linux

Published: April 13, 2021

Security Bulletin ID SB2021041393
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 25% Low 75%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Heap-based buffer overflow (CVE-ID: CVE-2021-20194)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/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 within the __cgroup_bpf_run_filter_getsockopt() function, when kernel is compiled with config params CONFIG_BPF_SYSCALL=y , CONFIG_BPF=y , CONFIG_CGROUPS=y , CONFIG_CGROUP_BPF=y , CONFIG_HARDENED_USERCOPY not set, and BPF hook to getsockopt is registered. A local user can trigger a heap-based buffer overflow and execute arbitrary code with elevated privileges.


2) Resource management error (CVE-ID: CVE-2021-26930)

CWE-ID: CWE-399 - Resource Management Errors

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources when processing service requests to the PV backend within drivers/block/xen-blkback/blkback.c driver in Xen. A local user on the guest OS can perform a denial of service (DoS) attack.


3) Allocation of resources without limits or throttling (CVE-ID: CVE-2021-26931)

CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling

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 allocation of resources without limits or throttling error within the scsiback_gnttab_data_map_batch() function in drivers/xen/xen-scsiback.c. A local user can perform a denial of service (DoS) attack.


4) Use-after-free (CVE-ID: CVE-2021-3348)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/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 authenticated user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the nbd_add_socket in drivers/block/nbd.c. A local authenticated user can trigger a use-after-free error and escalate privileges on the system.


Remediation

Install update from vendor's website.

References