Ubuntu 22.04 LTS : Linux kernel (OEM) vulnerabilities (USN-6343-1)

high Nessus Plugin ID 180545

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 22.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-6343-1 advisory.

- A hash collision flaw was found in the IPv6 connection lookup table in the Linux kernel's IPv6 functionality when a user makes a new kind of SYN flood attack. A user located in the local network or with a high bandwidth connection can increase the CPU usage of the server that accepts IPV6 connections up to 95%. (CVE-2023-1206)

- The fix for XSA-423 added logic to Linux'es netback driver to deal with a frontend splitting a packet in a way such that not all of the headers would come in one piece. Unfortunately the logic introduced there didn't account for the extreme case of the entire packet being split into as many pieces as permitted by the protocol, yet still being smaller than the area that's specially dealt with to keep all (possible) headers together. Such an unusual packet would therefore trigger a buffer overrun in the driver.
(CVE-2023-34319)

- An issue was discovered in l2cap_sock_release in net/bluetooth/l2cap_sock.c in the Linux kernel before 6.4.10. There is a use-after-free because the children of an sk are mishandled. (CVE-2023-40283)

- A flaw was found in KVM AMD Secure Encrypted Virtualization (SEV) in the Linux kernel. A KVM guest using SEV-ES or SEV-SNP with multiple vCPUs can trigger a double fetch race condition vulnerability and invoke the `VMGEXIT` handler recursively. If an attacker manages to call the handler multiple times, they can trigger a stack overflow and cause a denial of service or potentially guest-to-host escape in kernel configurations without stack guard pages (`CONFIG_VMAP_STACK`). (CVE-2023-4155)

- A flaw was found in the Linux kernel's TUN/TAP functionality. This issue could allow a local user to bypass network filters and gain unauthorized access to some resources. The original patches fixing CVE-2023-1076 are incorrect or incomplete. The problem is that the following upstream commits - a096ccca6e50 (tun: tun_chr_open(): correctly initialize socket uid), - 66b2c338adce (tap: tap_open():
correctly initialize socket uid), pass inode->i_uid to sock_init_data_uid() as the last parameter and that turns out to not be accurate. (CVE-2023-4194)

- A flaw was found in the exFAT driver of the Linux kernel. The vulnerability exists in the implementation of the file name reconstruction function, which is responsible for reading file name entries from a directory index and merging file name parts belonging to one file into a single long file name. Since the file name characters are copied into a stack variable, a local privileged attacker could use this flaw to overflow the kernel stack. (CVE-2023-4273)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected kernel package.

See Also

https://ubuntu.com/security/notices/USN-6343-1

Plugin Details

Severity: High

ID: 180545

File Name: ubuntu_USN-6343-1.nasl

Version: 1.4

Type: local

Agent: unix

Published: 9/6/2023

Updated: 1/9/2024

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2023-40283

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-6.1.0-1021-oem

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/6/2023

Vulnerability Publication Date: 6/27/2023

Reference Information

CVE: CVE-2023-1206, CVE-2023-34319, CVE-2023-40283, CVE-2023-4128, CVE-2023-4155, CVE-2023-4194, CVE-2023-4273

USN: 6343-1