CVE - CVE-2023-1998

CVE-ID
CVE-2023-1998	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
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.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://github.com/google/security-research/security/advisories/GHSA-mj4w-6495-6crx URL:https://github.com/google/security-research/security/advisories/GHSA-mj4w-6495-6crx MISC:https://github.com/torvalds/linux/commit/6921ed9049bc7457f66c1596c5b78aec0dae4a9d URL:https://github.com/torvalds/linux/commit/6921ed9049bc7457f66c1596c5b78aec0dae4a9d MISC:https://kernel.dance/#6921ed9049bc7457f66c1596c5b78aec0dae4a9d URL:https://kernel.dance/#6921ed9049bc7457f66c1596c5b78aec0dae4a9d MLIST:[debian-lts-announce] 20230502 [SECURITY] [DLA 3404-1] linux-5.10 security update URL:https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html MLIST:[debian-lts-announce] 20230503 [SECURITY] [DLA 3403-1] linux security update URL:https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html
Assigning CNA
Google LLC
Date Record Created
20230412	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20230412)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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