Ubuntu 16.04 ESM / 18.04 ESM : Linux kernel vulnerabilities (USN-6440-1)

high Nessus Plugin ID 183457

Synopsis

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

Description

The remote Ubuntu 16.04 ESM / 18.04 ESM host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-6440-1 advisory.

- A flaw possibility of memory leak in the Linux kernel cpu_entry_area mapping of X86 CPU data to memory was found in the way user can guess location of exception stack(s) or other important data. A local user could use this flaw to get access to some important data with expected location in memory. (CVE-2023-0597)

- 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)

- An issue was discovered in drivers/bluetooth/hci_ldisc.c in the Linux kernel 6.2. In hci_uart_tty_ioctl, there is a race condition between HCIUARTSETPROTO and HCIUARTGETPROTO. HCI_UART_PROTO_SET is set before hu->proto is set. A NULL pointer dereference may occur. (CVE-2023-31083)

- 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)

- A flaw was found in the Linux kernel's IP framework for transforming packets (XFRM subsystem). This issue may allow a malicious user with CAP_NET_ADMIN privileges to directly dereference a NULL pointer in xfrm_update_ae_params(), leading to a possible kernel crash and denial of service. (CVE-2023-3772)

- An integer overflow flaw was found in the Linux kernel. This issue leads to the kernel allocating `skb_shared_info` in the userspace, which is exploitable in systems without SMAP protection since `skb_shared_info` contains references to function pointers. (CVE-2023-42752)

- An array indexing vulnerability was found in the netfilter subsystem of the Linux kernel. A missing macro could lead to a miscalculation of the `h->nets` array offset, providing attackers with the primitive to arbitrarily increment/decrement a memory buffer out-of-bound. This issue may allow a local user to crash the system or potentially escalate their privileges on the system. (CVE-2023-42753)

- A flaw was found in the IPv4 Resource Reservation Protocol (RSVP) classifier in the Linux kernel. The xprt pointer may go beyond the linear part of the skb, leading to an out-of-bounds read in the `rsvp_classify` function. This issue may allow a local user to crash the system and cause a denial of service.
(CVE-2023-42755)

- A use-after-free vulnerability in the Linux kernel's af_unix component can be exploited to achieve local privilege escalation. The unix_stream_sendpage() function tries to add data to the last skb in the peer's recv queue without locking the queue. Thus there is a race where unix_stream_sendpage() could access an skb locklessly that is being released by garbage collection, resulting in use-after-free. We recommend upgrading past commit 790c2f9d15b594350ae9bca7b236f2b1859de02c. (CVE-2023-4622)

- A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation. If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free. We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f. (CVE-2023-4623)

- Rejected reason: CVE-2023-4881 was wrongly assigned to a bug that was deemed to be a non-security issue by the Linux kernel security team. (CVE-2023-4881)

- A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8. (CVE-2023-4921)

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-6440-1

Plugin Details

Severity: High

ID: 183457

File Name: ubuntu_USN-6440-1.nasl

Version: 1.1

Type: local

Agent: unix

Published: 10/20/2023

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-2023-4921

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: p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1156-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-219-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1171-azure, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1125-oracle, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-219-lowlatency, cpe:/o:canonical:ubuntu_linux:16.04:-:esm, cpe:/o:canonical:ubuntu_linux:18.04:-:esm, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1162-aws, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1146-kvm

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: 10/19/2023

Vulnerability Publication Date: 2/2/2023

Reference Information

CVE: CVE-2023-0597, CVE-2023-1206, CVE-2023-31083, CVE-2023-34319, CVE-2023-3772, CVE-2023-42752, CVE-2023-42753, CVE-2023-42755, CVE-2023-4622, CVE-2023-4623, CVE-2023-4881, CVE-2023-4921

USN: 6440-1