SB2021062328 - Ubuntu update for linux

CSH
CYBERSECURITY HELP
Sign In REGISTER

Main Vulnerability Database SB2021062328

SB2021062328 - Ubuntu update for linux

Published: June 23, 2021

Security Bulletin ID SB2021062328
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Medium 33% Low 67%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) Race condition (CVE-ID: CVE-2021-3609)

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:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green


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.


2) Out-of-bounds read (CVE-ID: CVE-2021-3600)

CWE-ID: CWE-125 - Out-of-bounds read

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.

The vulnerability exists due to out-of-bounds read error within the fixup_bpf_calls() function in kernel/bpf/verifier.c. A local user can execute arbitrary code.


3) Race condition (CVE-ID: CVE-2021-23133)

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: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 race condition in Linux kernel SCTP sockets (net/sctp/socket.c). If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock then an element is removed from the auto_asconf_splist list without any proper locking. This can be exploited by a local user with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some SCTP socket.


Remediation

Install update from vendor's website.

References