SB2023100562 - Ubuntu update for linux

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Main Vulnerability Database SB2023100562

SB2023100562 - Ubuntu update for linux

Published: October 5, 2023 Updated: January 4, 2026

Security Bulletin ID SB2023100562
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 6
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 17% Low 83%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 6 vulnerabilities.


1) Race condition (CVE-ID: CVE-2021-4001)

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

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/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 kernel/bpf/syscall.c in Linux kernel ebpf. A local user can exploit the race between bpf_map_update_elem and bpf_map_freeze and modify the frozen mapped address space.


2) Resource exhaustion (CVE-ID: CVE-2023-1206)

CWE-ID: CWE-400 - Resource exhaustion

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


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

The vulnerability exists due to a hash collision flaw in the IPv6 connection lookup table in the Linux kernel’s IPv6 functionality when an attacker makes a new kind of SYN flood attack. A remote attacker can increase the CPU usage of the server that accepts IPV6 connections up to 95%.


3) NULL pointer dereference (CVE-ID: CVE-2023-3212)

CWE-ID: CWE-476 - NULL Pointer Dereference

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 a NULL pointer dereference error within the gfs2 file system in the Linux kernel. A local user can perform a denial of service (DoS) attack.


4) NULL pointer dereference (CVE-ID: CVE-2023-3338)

CWE-ID: CWE-476 - NULL Pointer Dereference

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:P/U:Clear


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

The vulnerability exists due to a NULL pointer dereference error within the DECnet socket in net/decnet/dn_nsp_out.c. A local user can trigger a NULL pointer dereference and perform a denial of service (DoS) attack.


5) Use-after-free (CVE-ID: CVE-2023-3863)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 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/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 within the nfc_llcp_find_local() function in net/nfc/llcp_core.c in NFC implementation in Linux kernel. A local user can execute arbitrary code with elevated privileges.



6) Type Confusion (CVE-ID: CVE-2023-4194)

CWE-ID: CWE-843 - Type confusion

CVSSv4: 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/E:U/U:Clear


The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to a type confusion error in TUN/TAP functionality. A local user can bypass network filters and gain unauthorized access to some resources.

The vulnerability exists due to incomplete fix for #VU72742 (CVE-2023-1076).


Remediation

Install update from vendor's website.

References