CVE-2023-1998

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.
Configurations

Configuration 1 (hide)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

History

21 Nov 2024, 07:40

Type Values Removed Values Added
References () https://github.com/google/security-research/security/advisories/GHSA-mj4w-6495-6crx - Exploit, Third Party Advisory () https://github.com/google/security-research/security/advisories/GHSA-mj4w-6495-6crx - Exploit, Third Party Advisory
References () https://github.com/torvalds/linux/commit/6921ed9049bc7457f66c1596c5b78aec0dae4a9d - Patch () https://github.com/torvalds/linux/commit/6921ed9049bc7457f66c1596c5b78aec0dae4a9d - Patch
References () https://kernel.dance/#6921ed9049bc7457f66c1596c5b78aec0dae4a9d - Not Applicable () https://kernel.dance/#6921ed9049bc7457f66c1596c5b78aec0dae4a9d - Not Applicable
References () https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html - Mailing List, Third Party Advisory () https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html - Mailing List, Third Party Advisory
References () https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html - Mailing List, Third Party Advisory () https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html - Mailing List, Third Party Advisory

Information

Published : 2023-04-21 15:15

Updated : 2024-11-21 07:40


NVD link : CVE-2023-1998

Mitre link : CVE-2023-1998

CVE.ORG link : CVE-2023-1998


JSON object : View

Products Affected

debian

  • debian_linux

linux

  • linux_kernel
CWE
CWE-1303

Non-Transparent Sharing of Microarchitectural Resources

CWE-203

Observable Discrepancy