CVE-2023-0045
Incorrect indirect branch prediction barrier in the Linux Kernel
- Published
- Updated
- Reserved
- Assigned by
Description
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
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GoogleCNA (assigner) | 3.1 | Medium4.7 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 2.4% · top 16% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.7.
Weakness
Affected products
- affected 9137bb27e60e – < a664ec9158eeddd75121d39c9a0758016097fa96
References (5)
- https://git.kernel.org/tip/a664ec9158eeddd75121d39c9a0758016097fa96 (opens in a new tab)x_transferred
- https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html (opens in a new tab)x_transferred
- https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html (opens in a new tab)x_transferred
- https://security.netapp.com/advisory/ntap-20230714-0001/ (opens in a new tab)x_transferred
- https://github.com/google/security-research/security/advisories/GHSA-9x5g-vmxf-4qj8 (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2023-0045)Record last updated .