SynopsisThe remote Amazon Linux AMI host is missing a security update.
DescriptionThe version of kernel installed on the remote host is prior to 4.14.309-159.529. It is, therefore, affected by a vulnerability as referenced in the ALAS-2023-1701 advisory.
- A use-after-free vulnerability in the Linux Kernel traffic control index filter (tcindex) can be exploited to achieve local privilege escalation. The tcindex_delete function which does not properly deactivate filters in case of a perfect hashes while deleting the underlying structure which can later lead to double freeing the structure. A local attacker user can use this vulnerability to elevate its privileges to root.
We recommend upgrading past commit 8c710f75256bb3cf05ac7b1672c82b92c43f3d28. (CVE-2023-1829)
- A speculative pointer dereference problem exists in the Linux Kernel on the do_prlimit() function. The resource argument value is controlled and is used in pointer arithmetic for the 'rlim' variable and can be used to leak the contents. We recommend upgrading past version 6.1.8 or commit 739790605705ddcf18f21782b9c99ad7d53a8c11 (CVE-2023-0458)
- The Linux kernel allows userspace processes to enable mitigations by calling prctl with PR_SET_SPECULATION_CTRL which disables the speculation feature as well as by using seccomp. We had noticed that on VMs of at least one major cloud provider, the kernel still left the victim process exposed to attacks in some cases even after enabling the spectre-BTI mitigation with prctl. The same behavior can be observed on a bare-metal machine when forcing the mitigation to IBRS on boot command line. This happened because when plain IBRS was enabled (not enhanced IBRS), the kernel had some logic that determined that STIBP was not needed. The IBRS bit implicitly protects against cross-thread branch target injection.
However, with legacy IBRS, the IBRS bit was cleared on returning to userspace, due to performance reasons, which disabled the implicit STIBP and left userspace threads vulnerable to cross-thread branch target injection against which STIBP protects. (CVE-2023-1998)
- A use-after-free vulnerability was found in iscsi_sw_tcp_session_create in drivers/scsi/iscsi_tcp.c in SCSI sub-component in the Linux Kernel. In this flaw an attacker could leak kernel internal information.
- In the Linux kernel before 6.1.13, there is a double free in net/mpls/af_mpls.c upon an allocation failure (for registering the sysctl table under a new location) during the renaming of a device. (CVE-2023-26545)
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
SolutionRun 'yum update kernel' to update your system.
File Name: ala_ALAS-2023-1701.nasl
Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment
Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C
CPE: p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-i686, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:kernel-headers, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:perf-debuginfo, cpe:/o:amazon:linux
Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list
Exploit Ease: Exploits are available
Patch Publication Date: 3/17/2023
Vulnerability Publication Date: 2/25/2023