Vulnerability in Linux Kernel
CVE-2023-0045
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
EPSS: 0.024 (82.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve-coordination@google.com (Patch, Mailing List)
- cve-coordination@google.com (Mailing List, Third Party Advisory)
- cve-coordination@google.com (Mailing List, Third Party Advisory)
- cve-coordination@google.com (Third Party Advisory)
- cve-coordination@google.com (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2023-0045?
- CVE-2023-0045 is a medium-severity vulnerability in Linux Kernel, classified under Externally Controlled Reference to a Resource in Another Sphere. CVSS score: 4.7/10. Published 2023-04-25.
- How severe is CVE-2023-0045?
- Medium severity. CVSS v3 base score is 4.7 out of 10.
- Is CVE-2023-0045 known to be exploited?
- 10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.