Ubuntu 21.04 : Linux kernel (KVM) vulnerabilities (USN-4997-2)

medium Nessus Plugin ID 153127
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Synopsis

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

Description

The remote Ubuntu 21.04 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4997-2 advisory.

- The 802.11 standard that underpins Wi-Fi Protected Access (WPA, WPA2, and WPA3) and Wired Equivalent Privacy (WEP) doesn't require that received fragments be cleared from memory after (re)connecting to a network. Under the right circumstances, when another device sends fragmented frames encrypted using WEP, CCMP, or GCMP, this can be abused to inject arbitrary network packets and/or exfiltrate user data.
(CVE-2020-24586)

- The 802.11 standard that underpins Wi-Fi Protected Access (WPA, WPA2, and WPA3) and Wired Equivalent Privacy (WEP) doesn't require that all fragments of a frame are encrypted under the same key. An adversary can abuse this to decrypt selected fragments when another device sends fragmented frames and the WEP, CCMP, or GCMP encryption key is periodically renewed. (CVE-2020-24587)

- The 802.11 standard that underpins Wi-Fi Protected Access (WPA, WPA2, and WPA3) and Wired Equivalent Privacy (WEP) doesn't require that the A-MSDU flag in the plaintext QoS header field is authenticated.
Against devices that support receiving non-SSP A-MSDU frames (which is mandatory as part of 802.11n), an adversary can abuse this to inject arbitrary network packets. (CVE-2020-24588)

- An issue was discovered in the kernel in NetBSD 7.1. An Access Point (AP) forwards EAPOL frames to other clients even though the sender has not yet successfully authenticated to the AP. This might be abused in projected Wi-Fi networks to launch denial-of-service attacks against connected clients and makes it easier to exploit other vulnerabilities in connected clients. (CVE-2020-26139)

- An issue was discovered in the ALFA Windows 10 driver 6.1316.1209 for AWUS036H. The Wi-Fi implementation does not verify the Message Integrity Check (authenticity) of fragmented TKIP frames. An adversary can abuse this to inject and possibly decrypt packets in WPA or WPA2 networks that support the TKIP data- confidentiality protocol. (CVE-2020-26141)

- An issue was discovered on Samsung Galaxy S3 i9305 4.4.4 devices. The WEP, WPA, WPA2, and WPA3 implementations accept second (or subsequent) broadcast fragments even when sent in plaintext and process them as full unfragmented frames. An adversary can abuse this to inject arbitrary network packets independent of the network configuration. (CVE-2020-26145)

- An issue was discovered in the Linux kernel 5.8.9. The WEP, WPA, WPA2, and WPA3 implementations reassemble fragments even though some of them were sent in plaintext. This vulnerability can be abused to inject packets and/or exfiltrate selected fragments when another device sends fragmented frames and the WEP, CCMP, or GCMP data-confidentiality protocol is used. (CVE-2020-26147)

- An out-of-bounds (OOB) memory access flaw was found in fs/f2fs/node.c in the f2fs module in the Linux kernel in versions before 5.12.0-rc4. A bounds check failure allows a local attacker to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability. (CVE-2021-3506)

- A flaw null pointer dereference in the Nitro Enclaves kernel driver was found in the way that Enclaves VMs forces closures on the enclave file descriptor. A local user of a host machine could use this flaw to crash the system or escalate their privileges on the system. (CVE-2021-3543)

- A race condition in Linux kernel SCTP sockets (net/sctp/socket.c) before 5.12-rc8 can lead to kernel privilege escalation from the context of a network service or an unprivileged process. If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock then an element is removed from the auto_asconf_splist list without any proper locking. This can be exploited by an attacker with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some SCTP socket. (CVE-2021-23133)

- Use After Free vulnerability in nfc sockets in the Linux Kernel before 5.12.4 allows local attackers to elevate their privileges. In typical configurations, the issue can only be triggered by a privileged local user with the CAP_NET_RAW capability. (CVE-2021-23134)

- This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel 5.11.15. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of eBPF programs. The issue results from the lack of proper validation of user-supplied eBPF programs prior to executing them.
An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel. Was ZDI-CAN-13661. (CVE-2021-31440)

- kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. Also, the BPF stack can contain uninitialized data that might represent sensitive information previously operated on by the kernel. (CVE-2021-31829)

- net/bluetooth/hci_request.c in the Linux kernel through 5.12.2 has a race condition for removal of the HCI controller. (CVE-2021-32399)

- In the Linux kernel before 5.12.4, net/bluetooth/hci_event.c has a use-after-free when destroying an hci_chan, aka CID-5c4c8c954409. This leads to writing an arbitrary value. (CVE-2021-33034)

- kernel/bpf/verifier.c in the Linux kernel through 5.12.7 enforces incorrect limits for pointer arithmetic operations, aka CID-bb01a1bba579. This can be abused to perform out-of-bounds reads and writes in kernel memory, leading to local privilege escalation to root. In particular, there is a corner case where the off reg causes a masking direction change, which then results in an incorrect final aux->alu_limit.
(CVE-2021-33200)

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 packages.

See Also

https://ubuntu.com/security/notices/USN-4997-2

Plugin Details

Severity: Medium

ID: 153127

File Name: ubuntu_USN-4997-2.nasl

Version: 1.2

Type: local

Agent: unix

Published: 9/8/2021

Updated: 9/8/2021

Dependencies: ssh_get_info.nasl, linux_alt_patch_detect.nasl

Risk Information

CVSS Score Source: CVE-2021-3543

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: Medium

Base Score: 6.7

Temporal Score: 5.8

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

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:21.04, p-cpe:/a:canonical:ubuntu_linux:linux-buildinfo-5.11.0-1009-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-headers-5.11.0-1009-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-headers-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.11.0-1009-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-image-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-image-unsigned-5.11.0-1009-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-kvm-headers-5.11.0-1009, p-cpe:/a:canonical:ubuntu_linux:linux-kvm-tools-5.11.0-1009, p-cpe:/a:canonical:ubuntu_linux:linux-modules-5.11.0-1009-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-tools-5.11.0-1009-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-tools-kvm

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

Exploit Ease: No known exploits are available

Patch Publication Date: 6/25/2021

Vulnerability Publication Date: 4/19/2021

Reference Information

CVE: CVE-2020-24586, CVE-2020-24587, CVE-2020-24588, CVE-2020-26139, CVE-2020-26141, CVE-2020-26145, CVE-2020-26147, CVE-2021-3506, CVE-2021-3543, CVE-2021-3609, CVE-2021-23133, CVE-2021-23134, CVE-2021-31440, CVE-2021-31829, CVE-2021-32399, CVE-2021-33034, CVE-2021-33200

USN: 4997-2

IAVA: 2021-A-0223-S, 2021-A-0222-S