Rapid7 Vulnerability & Exploit Database

Oracle Linux: CVE-2023-1998: ELSA-2023-4377: kernel security, bug fix, and enhancement update (IMPORTANT) (Multiple Advisories)

Free InsightVM Trial No Credit Card Necessary
2024 Attack Intel Report Latest research by Rapid7 Labs
Back to Search

Oracle Linux: CVE-2023-1998: ELSA-2023-4377: kernel security, bug fix, and enhancement update (IMPORTANT) (Multiple Advisories)

Severity
4
CVSS
(AV:L/AC:H/Au:S/C:C/I:N/A:N)
Published
04/12/2023
Created
08/04/2023
Added
08/03/2023
Modified
12/06/2024

Description

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. It was found that the Linux Kernel still left the victim process exposed to attacks in some cases even after enabling the spectre-BTI mitigation with prctl. The kernel failed to protect applications that attempted to protect against Spectre v2 leaving them open to attack from other processes running on the same physical core in another hyperthread.

Solution(s)

  • oracle-linux-upgrade-kernel

insightVM

Advanced vulnerability management analytics and reporting.
Key Features
  • Lightweight Endpoint Agent
  • Live Dashboards
  • Real Risk Prioritization
  • IT-Integrated Remediation Projects
  • Cloud, Virtual, and Container Assessment
  • Integrated Threat Feeds
  • Easy-to-Use RESTful API
  • Automation-Assisted Patching
  • Automated Containment
Free InsightVM Trial View All Features

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;