Amazon Linux 2 : kernel (ALASKERNEL-5.15-2023-015)

high Nessus Plugin ID 173235

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 5.15.102-61.139. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.15-2023-015 advisory.

- A regression exists in the Linux Kernel within KVM: nVMX that allowed for speculative execution attacks.
L2 can carry out Spectre v2 attacks on L1 due to L1 thinking it doesn't need retpolines or IBPB after running L2 due to KVM (L0) advertising eIBRS support to L1. An attacker at L2 with code execution can execute code on an indirect branch on the host machine. We recommend upgrading to Kernel 6.2 or past commit 2e7eab81425a (CVE-2022-2196)

- When SMT is enabled, certain AMD processors may speculatively execute instructions using a target from the sibling thread after an SMT mode switch potentially resulting in information disclosure. (CVE-2022-27672)

- 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)

- In the Linux kernel, pick_next_rt_entity() may return a type confused entry, not detected by the BUG_ON condition, as the confused entry will not be NULL, but list_head.The buggy error condition would lead to a type confused entry with the list head,which would then be used as a type confused sched_rt_entity,causing memory corruption. (CVE-2023-1077)

- A flaw was found in the Linux Kernel in RDS (Reliable Datagram Sockets) protocol. The rds_rm_zerocopy_callback() uses list_entry() on the head of a list causing a type confusion. Local user can trigger this with rds_message_put(). Type confusion leads to `struct rds_msg_zcopy_info *info` actually points to something else that is potentially controlled by local user. It is known how to trigger this, which causes an out of bounds access, and a lock corruption. (CVE-2023-1078)

- Use After Free vulnerability in Linux kernel traffic control index filter (tcindex) allows Privilege Escalation. The imperfect hash area can be updated while packets are traversing, which will cause a use- after-free when 'tcf_exts_exec()' is called with the destroyed tcf_ext. A local attacker user can use this vulnerability to elevate its privileges to root. This issue affects Linux Kernel: from 4.14 before git commit ee059170b1f7e94e55fa6cadee544e176a6e59c2. (CVE-2023-1281)

- 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)

- 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)

- 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)

- A use after free flaw was found in hfsplus_put_super in fs/hfsplus/super.c in the Linux Kernel. This flaw could allow a local user to cause a denial of service problem. (CVE-2023-2985)

- An issue was discovered in lib/kobject.c in the Linux kernel before 6.2.3. With root access, an attacker can trigger a race condition that results in a fill_kobj_path out-of-bounds write. (CVE-2023-45863)

- A memory leak problem was found in ctnetlink_create_conntrack in net/netfilter/nf_conntrack_netlink.c in the Linux Kernel. This issue may allow a local attacker with CAP_NET_ADMIN privileges to cause a denial of service (DoS) attack due to a refcount overflow. (CVE-2023-7192)

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.

See Also

https://alas.aws.amazon.com/AL2/ALASKERNEL-5.15-2023-015.html

https://alas.aws.amazon.com/faqs.html

https://alas.aws.amazon.com/cve/html/CVE-2022-2196.html

https://alas.aws.amazon.com/cve/html/CVE-2022-27672.html

https://alas.aws.amazon.com/cve/html/CVE-2023-0458.html

https://alas.aws.amazon.com/cve/html/CVE-2023-1077.html

https://alas.aws.amazon.com/cve/html/CVE-2023-1078.html

https://alas.aws.amazon.com/cve/html/CVE-2023-1281.html

https://alas.aws.amazon.com/cve/html/CVE-2023-1829.html

https://alas.aws.amazon.com/cve/html/CVE-2023-1998.html

https://alas.aws.amazon.com/cve/html/CVE-2023-26545.html

https://alas.aws.amazon.com/cve/html/CVE-2023-2985.html

https://alas.aws.amazon.com/cve/html/CVE-2023-45863.html

https://alas.aws.amazon.com/cve/html/CVE-2023-7192.html

Plugin Details

Severity: High

ID: 173235

File Name: al2_ALASKERNEL-5_15-2023-015.nasl

Version: 1.8

Type: local

Agent: unix

Published: 3/22/2023

Updated: 1/23/2024

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

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

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

CVSS Score Source: CVE-2023-1829

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

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

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS Score Source: CVE-2022-2196

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:bpftool, p-cpe:/a:amazon:linux:bpftool-debuginfo, p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64, 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-livepatch-5.15.102-61.139, 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, p-cpe:/a:amazon:linux:python-perf, p-cpe:/a:amazon:linux:python-perf-debuginfo, cpe:/o:amazon:linux:2

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/17/2023

Vulnerability Publication Date: 1/9/2023

Reference Information

CVE: CVE-2022-2196, CVE-2022-27672, CVE-2023-0458, CVE-2023-1077, CVE-2023-1078, CVE-2023-1281, CVE-2023-1829, CVE-2023-1998, CVE-2023-26545, CVE-2023-2985, CVE-2023-45863, CVE-2023-7192