Synopsis
The remote Amazon Linux 2 host is missing a security update.
Description
The version of kernel installed on the remote host is prior to 5.4.190-107.353. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.4-2024-076 advisory.
When the KVM updates the guest's page table entry, it will first use get_user_pages_fast() to pin the page, and when it fails (e.g. the vma->flags has VM_IO or VM_PFNMAP), it will get corresponding VMA where the page lies in through find_vma_intersection(), calculate the physical address, and map the page to the kernel virtual address through memremap(), and finally, write the update.The problem is that when we get the vma through find_vma_intersection(), only VM_PFNMAP is checked, not both VM_IO and VM_PFNMAP. In the reproducer below, after the KVM_SET_USER_MEMORY_REGION is completed, we replace the guest's memory mapping with the kernel-user shared region of io_uring and then perform the KVM_TRANSLATE operation, which finally triggers the page table entry update. Now, memremap() will return page_offset_base (direct mapping of all physical memory) + vaddr (the linear address of KVM_TRANSLATE) + vm_pgoff (the offset when io_uring performs mmap(2)), and use the return value as the base address for CMPXCHG (write 0x21 in this case).
Since both vaddr and vm_pgoff are controllable by the user-mode process, writing may exceed the previously mapped guest memory space and trigger exceptions such as UAF. The vulnerability shares similarities with CVE-2021-22543. (CVE-2022-1158)
A vulnerability was found in the pfkey_register function in net/key/af_key.c in the Linux kernel. This flaw allows a local, unprivileged user to gain access to kernel memory, leading to a system crash or a leak of internal kernel information. (CVE-2022-1353)
A flaw was found in the Linux kernel implementation of proxied virtualized TPM devices. On a system where virtualized TPM devices are configured (this is not the default) a local attacker can create a use-after- free and create a situation where it may be possible to escalate privileges on the system. (CVE-2022-2977)
A flaw was found in the Linux kernel. A NULL pointer dereference may occur while a slip driver is in progress to detach in sl_tx_timeout in drivers/net/slip/slip.c. This issue could allow an attacker to crash the system or leak internal kernel information. (CVE-2022-41858)
In the Linux kernel, the following vulnerability has been resolved:
swiotlb: fix info leak with DMA_FROM_DEVICE (CVE-2022-48853)
A flaw that boot CPU could be vulnerable for the speculative execution behavior kind of attacks in the Linux kernel X86 CPU Power management options functionality was found in the way user resuming CPU from suspend-to-RAM. A local user could use this flaw to potentially get unauthorized access to some memory of the CPU similar to the speculative execution behavior kind of attacks. (CVE-2023-1637)
Tenable has extracted the preceding description block directly from the tested product security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Run 'yum update kernel' to update your system.
Plugin Details
File Name: al2_ALASKERNEL-5_4-2024-076.nasl
Agent: unix
Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus
Risk Information
Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:P
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:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:python-perf-debuginfo, p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-headers, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:bpftool-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:python-perf, p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:bpftool, p-cpe:/a:amazon:linux:perf-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64, p-cpe:/a:amazon:linux:kernel-tools
Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list
Exploit Ease: Exploits are available
Patch Publication Date: 7/24/2024
Vulnerability Publication Date: 4/29/2022