SB2021092819 - Ubuntu update for linux

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Main Vulnerability Database SB2021092819

SB2021092819 - Ubuntu update for linux

Published: September 28, 2021

Security Bulletin ID SB2021092819
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 20% Low 80%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 vulnerabilities.


1) Type Confusion (CVE-ID: CVE-2021-33624)

CWE-ID: CWE-843 - Type confusion

CVSSv4: 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/E:P/U:Clear


The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to a type confusion error within kernel/bpf/verifier.c in the Linux kernel. A an unprivileged BPF program can read arbitrary memory locations via a side-channel attack.


2) Resource exhaustion (CVE-ID: CVE-2021-3679)

CWE-ID: CWE-400 - Resource exhaustion

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/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 lack of CPU resource in the Linux kernel tracing module functionality when using trace ring buffer in a specific way. A privileged local user (with CAP_SYS_ADMIN capability) could use this flaw to starve the resources causing denial of service.


3) Out-of-bounds write (CVE-ID: CVE-2021-37576)

CWE-ID: CWE-787 - Out-of-bounds write

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


The vulnerability allows a remote user to escalate privileges on the system.

The vulnerability exists due to a boundary error in arch/powerpc/kvm/book3s_rtas.c in the Linux kernel through 5.13.5 on the powerpc platform. An attacker on KVM guest OS can cause host OS memory corruption via rtas_args.nargs and execute arbitrary code on the host OS.


4) Race condition (CVE-ID: CVE-2021-38199)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to fs/nfs/nfs4client.c in the Linux kernel has incorrect connection-setup ordering. A remote attacker with access to a remote NFSv4 server can perform a denial of service (DoS) attack by arranging the server to be unreachable during trunking detection.


5) Use-after-free (CVE-ID: CVE-2021-38204)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a local attacker to perform a denial of service attack.

The vulnerability exists due to a use-after-free error in the drivers/usb/host/max3421-hcd.c in the Linux kernel. An attacker with physical access to the system can remove a MAX-3421 USB device to perform a denial of service attack.


Remediation

Install update from vendor's website.

References