Information Exposure Affecting kernel-default package, versions <5.3.18-150300.59.121.2


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

Exploit Maturity
Mature
EPSS
0.06% (25th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-SLES153-KERNELDEFAULT-5508350
  • published10 May 2023
  • disclosed9 May 2023

Introduced: 9 May 2023

CVE-2023-1998  (opens in a new tab)
CWE-203  (opens in a new tab)

How to fix?

Upgrade SLES:15.3 kernel-default to version 5.3.18-150300.59.121.2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-default package and not the kernel-default package as distributed by SLES. See How to fix? for SLES:15.3 relevant fixed versions and status.

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.

CVSS Scores

version 3.1