SB2023101067 - Red Hat Enterprise Linux 9.0 Extended Update Support update for kernel
Published: October 10, 2023 Updated: January 4, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 8 vulnerabilities.
1) 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%.
2) Security features bypass (CVE-ID: CVE-2023-1998)
CWE-ID: CWE-254 - Security Features
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Clear
The vulnerability allows a local user to bypass implemented security restrictions.
The vulnerability exists due to incorrect implementation of the Spectre v2 SMT mitigations, related to calling prctl with PR_SET_SPECULATION_CTRL. An attacker can gain unauthorized access to kernel memory from userspace.
3) NULL pointer dereference (CVE-ID: CVE-2023-28327)
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 unix_diag_get_exact() function in net/unix/diag.c. A local user can perform a denial of service (DoS) attack.
4) Use-after-free (CVE-ID: CVE-2023-31248)
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 nft_chain_lookup_byid() function, which failed to check whether a chain was active and CAP_NET_ADMIN is in any user or network namespace. A local user ca trigger a use-after-free error and execute arbitrary code with elevated privileges.
5) Incorrect calculation (CVE-ID: CVE-2023-3161)
CWE-ID: CWE-682 - Incorrect Calculation
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 incorrect calculation in the Framebuffer Console (fbcon) in the Linux kernel. A local user can perform a denial of service (DoS) attack.
6) Out-of-bounds write (CVE-ID: CVE-2023-35001)
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:P/U:Clear
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error within the nft_byteorder() function. A local user can trigger an out-of-bounds write and execute arbitrary code on the target system.
7) Out-of-bounds write (CVE-ID: CVE-2023-35788)
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 within the fl_set_geneve_opt() function in net/sched/cls_flower.c in Linux kernel. A local user can trigger an out-of-bounds write and execute arbitrary code with elevated privileges.
8) Use-after-free (CVE-ID: CVE-2023-4128)
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 within net/sched/cls_fw.c in classifiers (cls_fw, cls_u32, and cls_route) in the Linux Kernel. A local user can trigger a use-after-free error and execute arbitrary code with elevated privileges.
Remediation
Install update from vendor's website.