Ubuntu 20.04 LTS : Linux kernel (OEM) vulnerabilities (USN-5096-1)

high Nessus Plugin ID 153789

Synopsis

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

Description

The remote Ubuntu 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-5096-1 advisory.

- An out-of-bounds memory write flaw was found in the Linux kernel's joystick devices subsystem in versions before 5.9-rc1, in the way the user calls ioctl JSIOCSBTNMAP. This flaw allows a local user to crash the system or possibly escalate their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (CVE-2021-3612)

- A lack of CPU resource in the Linux kernel tracing module functionality in versions prior to 5.14-rc3 was found in the way user uses trace ring buffer in a specific way. Only privileged local users (with CAP_SYS_ADMIN capability) could use this flaw to starve the resources causing denial of service.
(CVE-2021-3679)

- In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack. (CVE-2021-34556)

- In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because a certain preempting store operation does not necessarily occur before a store operation that has an attacker-controlled value.
(CVE-2021-35477)

- hso_free_net_device in drivers/net/usb/hso.c in the Linux kernel through 5.13.4 calls unregister_netdev without checking for the NETREG_REGISTERED state, leading to a use-after-free and a double free.
(CVE-2021-37159)

- ** DISPUTED ** In drivers/char/virtio_console.c in the Linux kernel before 5.13.4, data corruption or loss can be triggered by an untrusted device that supplies a buf->len value exceeding the buffer size. NOTE:
the vendor indicates that the cited data corruption is not a vulnerability in any existing use case; the length validation was added solely for robustness in the face of anomalous host OS behavior.
(CVE-2021-38160)

- In kernel/bpf/hashtab.c in the Linux kernel through 5.13.8, there is an integer overflow and out-of-bounds write when many elements are placed in a single bucket. NOTE: exploitation might be impractical without the CAP_SYS_ADMIN capability. (CVE-2021-38166)

- fs/nfs/nfs4client.c in the Linux kernel before 5.13.4 has incorrect connection-setup ordering, which allows operators of remote NFSv4 servers to cause a denial of service (hanging of mounts) by arranging for those servers to be unreachable during trunking detection. (CVE-2021-38199)

- net/sunrpc/xdr.c in the Linux kernel before 5.13.4 allows remote attackers to cause a denial of service (xdr_set_page_base slab-out-of-bounds access) by performing many NFS 4.2 READ_PLUS operations.
(CVE-2021-38201)

- fs/nfsd/trace.h in the Linux kernel before 5.13.4 might allow remote attackers to cause a denial of service (out-of-bounds read in strlen) by sending NFS traffic when the trace event framework is being used for nfsd. (CVE-2021-38202)

- btrfs in the Linux kernel before 5.13.4 allows attackers to cause a denial of service (deadlock) via processes that trigger allocation of new system chunks during times when there is a shortage of free space in the system space_info. (CVE-2021-38203)

- drivers/usb/host/max3421-hcd.c in the Linux kernel before 5.13.6 allows physically proximate attackers to cause a denial of service (use-after-free and panic) by removing a MAX-3421 USB device in certain situations. (CVE-2021-38204)

- drivers/net/ethernet/xilinx/xilinx_emaclite.c in the Linux kernel before 5.13.3 makes it easier for attackers to defeat an ASLR protection mechanism because it prints a kernel pointer (i.e., the real IOMEM pointer). (CVE-2021-38205)

- A race condition was discovered in ext4_write_inline_data_end in fs/ext4/inline.c in the ext4 subsystem in the Linux kernel through 5.13.13. (CVE-2021-40490)

- loop_rw_iter in fs/io_uring.c in the Linux kernel 5.10 through 5.14.6 allows local users to gain privileges by using IORING_OP_PROVIDE_BUFFERS to trigger a free of a kernel buffer, as demonstrated by using /proc//maps for exploitation. (CVE-2021-41073)

Note that Nessus has not tested for this issue 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-5096-1

Plugin Details

Severity: High

ID: 153789

File Name: ubuntu_USN-5096-1.nasl

Version: 1.4

Type: local

Agent: unix

Published: 9/30/2021

Updated: 10/20/2023

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.6

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

CVSS Score Source: CVE-2021-41073

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:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.13.0-1014-oem

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/29/2021

Vulnerability Publication Date: 7/9/2021

Reference Information

CVE: CVE-2021-34556, CVE-2021-35477, CVE-2021-3612, CVE-2021-3679, CVE-2021-37159, CVE-2021-3732, CVE-2021-38160, CVE-2021-38166, CVE-2021-38199, CVE-2021-38201, CVE-2021-38202, CVE-2021-38203, CVE-2021-38204, CVE-2021-38205, CVE-2021-40490, CVE-2021-41073

USN: 5096-1