CVE-2023-0045: Debian Linux

High severity, CVSS 7.5. EPSS: 2.4% chance of exploitation in the next 30 days.

The current implementation of the prctl syscall does not issue an IBPB immediately during the syscall. The ib_prctl_set  function updates the Thread Information Flags (TIFs) for the task and updates the SPEC_CTRL MSR on the function __speculation_ctrl_update, but the IBPB is only issued on the next schedule, when the TIF bits are checked. This leaves the victim vulnerable to values already injected on the BTB, prior to the prctl syscall.  The patch that added the support for the conditional mitigation via prctl (ib_prctl_set) dates back to the kernel 4.9.176. We recommend upgrading past commit a664ec9158eeddd75121d39c9a0758016097fa96

Affected products

• Debian Debian Linux: version 10.0 only
• Linux Linux Kernel: from 3.16.68, before 3.17 (fixed in 3.17); from 4.4.180, before 4.5 (fixed in 4.5); from 4.9.176, before 4.10 (fixed in 4.10); from 4.14.86, before 4.14.303 (fixed in 4.14.303); from 4.19.7, before 4.19.270 (fixed in 4.19.270); from 4.20, before 5.4.229 (fixed in 5.4.229); …
• Netapp Active Iq Unified Manager: affected versions not specified
• Netapp h300s Firmware: affected versions not specified
• Netapp h410c Firmware: affected versions not specified
• Netapp h410s Firmware: affected versions not specified
• Netapp h500s Firmware: affected versions not specified
• Netapp h700s Firmware: affected versions not specified

Published 2023-04-25. Last modified 2026-06-17.