Detections
Analytics

CBL Mariner 2.0 Security Update: kernel (CVE-2023-1998)

medium Nessus Plugin ID 176615

Synopsis

The remote CBL Mariner host is missing one or more security updates.

Description

The version of kernel installed on the remote CBL Mariner 2.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2023-1998 advisory.

 - 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)

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://nvd.nist.gov/vuln/detail/CVE-2023-1998

Plugin Details

Severity: Medium

ID: 176615

File Name: mariner_kernel_CVE-2023-1998.nasl

Version: 1.0

Type: local

Published: 6/2/2023

Updated: 6/2/2023

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.2

CVSS v2

Risk Factor: Low

Base Score: 3.8

Temporal Score: 3

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

CVSS Score Source: CVE-2023-1998

CVSS v3

Risk Factor: Medium

Base Score: 5.6

Temporal Score: 5.1

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

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

Vulnerability Information

CPE: p-cpe:/a:microsoft:cbl-mariner:bpftool, p-cpe:/a:microsoft:cbl-mariner:kernel, p-cpe:/a:microsoft:cbl-mariner:kernel-debuginfo, p-cpe:/a:microsoft:cbl-mariner:kernel-devel, p-cpe:/a:microsoft:cbl-mariner:kernel-docs, p-cpe:/a:microsoft:cbl-mariner:kernel-drivers-accessibility, p-cpe:/a:microsoft:cbl-mariner:kernel-drivers-gpu, p-cpe:/a:microsoft:cbl-mariner:kernel-drivers-sound, p-cpe:/a:microsoft:cbl-mariner:kernel-dtb, p-cpe:/a:microsoft:cbl-mariner:kernel-oprofile, p-cpe:/a:microsoft:cbl-mariner:kernel-tools, p-cpe:/a:microsoft:cbl-mariner:python3-perf, x-cpe:/o:microsoft:cbl-mariner

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/9/2023

Vulnerability Publication Date: 3/17/2023

Reference Information

CVE: CVE-2023-1998