CVE-2023-0045: Incorrect indirect branch prediction barrier in the Linux Kernel
Vulnerability summary
CVE-2023-0045 is a high (CVSS 7.5) vulnerability in debian debian_linux. EPSS estimates a 2.40% chance of exploitation in the next 30 days, higher than 84% of scored vulnerabilities. 1 public exploit is recorded.
Not severe (CVSS 4.7, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 42 · Related 40Timeline
- 25-04-2023PublishedVulnerability first disclosed.
- 13-02-2025Last modifiedVulnerability information updated.
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
CVSS metrics
4 scores · 4 sources · 1 version- CVE.orgCNA4.7MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:NDiffers
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
2.40%
Chance of exploitation in the next 30 days
Percentile
84%
Versus all other CVEs
30-day change
No change 0.00 pp
From 2.40% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundSecurity Research
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu91 products
- linux< 4.4.0-237.271 | < 4.15.0-208.220 | < 5.4.0-144.161 | < 5.15.0-69.76
- linux-aws< 4.4.0-1116.122 | < 4.4.0-1154.169 | < 4.15.0-1153.166 | < 5.4.0-1097.105 | < 5.15.0-1033.37
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
- linux-aws-5.13All versions (No fix recorded)
Netapp6 products
Debian2 products
- linux< 6.1.7-1
- debian_linuxEOL10.0
Linux1 product
- linux_kernel≥ 9137bb27e60e, < a664ec9158eeddd75121d39c9a0758016097fa96 | ≥ 3.16.68, < 3.17 | ≥ 4.4.180, < 4.5 | ≥ 4.9.176, < 4.10 | ≥ 4.14.86, < 4.14.303 | ≥ 4.19.7, < 4.19.270 | ≥ 4.20, < 5.4.229 | ≥ 5.5.0, < 5.10.163 | ≥ 5.11, < 5.15.87 | ≥ 5.16, < 6.0.19 | ≥ 6.1, < 6.1.5
4 vendors · 100 products
References
36 links
- security.netapp.com/advisory/ntap-20230714-0001/Third Party Advisory
- github.com/google/security-research/security/advisories/GHSA-9x5g-vmxf-4qj8ExploitThird Party Advisory
- git.kernel.org/pub/…REPORT
- git.kernel.org/pub/…REPORT