SynopsisThe remote Amazon Linux 2 host is missing a security update.
DescriptionThe version of kernel installed on the remote host is prior to 5.10.47-39.130. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.10-2022-002 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.
- 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)
- The Linux kernel through 5.8.13 does not properly enforce the Secure Boot Forbidden Signature Database (aka dbx) protection mechanism. This affects certs/blacklist.c and certs/system_keyring.c.
- Bluetooth LE and BR/EDR secure pairing in Bluetooth Core Specification 2.1 through 5.2 may permit a nearby man-in-the-middle attacker to identify the Passkey used during pairing (in the Passkey authentication procedure) by reflection of the public key and the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. The attack methodology determines the Passkey value one bit at a time. (CVE-2020-26558)
- Improper access control in BlueZ may allow an authenticated user to potentially enable information disclosure via adjacent access. (CVE-2021-0129)
- An issue was discovered in Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users with the ability to start and control a VM to read/write random pages of memory and can result in local privilege escalation. (CVE-2021-22543)
- Guest triggered use-after-free in Linux xen-netback A malicious or buggy network PV frontend can force Linux netback to disable the interface and terminate the receive kernel thread associated with queue 0 in response to the frontend sending a malformed packet. Such kernel thread termination will lead to a use- after-free in Linux netback when the backend is destroyed, as the kernel thread associated with queue 0 will have already exited and thus the call to kthread_stop will be performed against a stale pointer.
- 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)
- 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)
- In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db. (CVE-2021-33624)
- net/can/bcm.c in the Linux kernel through 5.12.10 allows local users to obtain sensitive information from kernel stack memory because parts of a data structure are uninitialized. (CVE-2021-34693)
- The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee (bpf, ringbuf: Deny reserve of buffers larger than ringbuf) (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced via 457f44363a88 (bpf: Implement BPF ring buffer and verifier support for it) (v5.8-rc1). (CVE-2021-3489)
- The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e (bpf: Fix alu32 const subreg bound tracking on bitwise operations) (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 (bpf: Verifier, do explicit ALU32 bounds tracking) (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 (bpf:Fix a verifier failure with xor) ( 5.10-rc1). (CVE-2021-3490)
- The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being usedin mem_rw when reading /proc/<PID>/mem.
This could be used to create a heap overflow leading to arbitrary code execution in the kernel. It was addressed via commit d1f82808877b (io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers) (v5.13-rc1) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced in ddf0322db79c (io_uring: add IORING_OP_PROVIDE_BUFFERS) (v5.7-rc1). (CVE-2021-3491)
- 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 flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious HCI TTY Bluetooth device. A local user could use this flaw to crash the system. This flaw affects all the Linux kernel versions starting from 3.13. (CVE-2021-3564)
- A use-after-free in function hci_sock_bound_ioctl() of the Linux kernel HCI subsystem was found in the way user calls ioct HCIUNBLOCKADDR or other way triggers race condition of the call hci_unregister_dev() together with one of the calls hci_sock_blacklist_add(), hci_sock_blacklist_del(), hci_get_conn_info(), hci_get_auth_info(). A privileged local user could use this flaw to crash the system or escalate their privileges on the system. This flaw affects the Linux kernel versions prior to 5.13-rc5. (CVE-2021-3573)
- net/nfc/llcp_sock.c in the Linux kernel before 5.12.10 allows local unprivileged users to cause a denial of service (NULL pointer dereference and BUG) by making a getsockname call after a certain type of failure of a bind call. (CVE-2021-38208)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
SolutionRun 'yum update kernel' to update your system.
File Name: al2_ALASKERNEL-5_10-2022-002.nasl
Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent
Temporal Vector: CVSS2#E:F/RL:OF/RC:C
Temporal Vector: CVSS:3.0/E:F/RL:O/RC:C
CPE: cpe:2.3:o:amazon:linux:2:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-debuginfo:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-debuginfo-common-x86_64:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-devel:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-headers:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-tools:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-tools-debuginfo:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-tools-devel:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:perf:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:perf-debuginfo:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:python-perf:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:python-perf-debuginfo:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-debuginfo-common-aarch64:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:bpftool:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:bpftool-debuginfo:*:*:*:*:*:*:*
Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list
Exploit Ease: Exploits are available
Patch Publication Date: 1/20/2022
Vulnerability Publication Date: 10/2/2020
Metasploit (Linux eBPF ALU32 32-bit Invalid Bounds Tracking LPE)
CVE: CVE-2020-26541, CVE-2021-3506, CVE-2021-32399, CVE-2020-24588, CVE-2020-24587, CVE-2020-24586, CVE-2020-26139, CVE-2020-26145, CVE-2020-26147, CVE-2020-26141, CVE-2021-3489, CVE-2021-3490, CVE-2021-3491, CVE-2021-33034, CVE-2021-31440, CVE-2020-26558, CVE-2021-22543, CVE-2021-3564, CVE-2021-3543, CVE-2021-0129, CVE-2021-3573, CVE-2021-34693, CVE-2021-33624, CVE-2021-28691, CVE-2021-38208
IAVA: 2021-A-0223-S, 2021-A-0222-S