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CVE-2023-0045· NVD / CVE Program· CNA Google

Incorrect indirect branch prediction barrier in the Linux Kernel

Noroxi assessment

Priority: Monitor (action score 31/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 2.3% (FIRST EPSS); higher than 83.7% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux Kernel a664ec9158eeddd75121d39c9a0758016097fa96.
  • Severity is disputed: the assigning authority (CNA) scores it 4.7, NVD 7.5.
  • Mentioned 3 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux Kernel a664ec9158eeddd75121d39c9a0758016097fa96 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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

HighCVSS 7.5 · v3.1—Proof of concept Fix available
Published
Apr 25, 2023
Updated
Jun 17, 2026
EPSS
2.3% · 83th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.3%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.5
CNA · Google
4.7
2.8 point gap

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-0045

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel
debiandebian linux
netappactive iq unified manager
netapph300s firmware
netapph300s
netapph500s firmware
netapph500s
netapph700s firmware
netapph700s
netapph410s firmware
netapph410s
netapph410c firmware

and 1 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • debian debian linux10.0
  • linux linux kernel4.4.180 and later · before 4.5
  • linux linux kernel4.9.176 and later · before 4.10
  • linux linux kernel4.14.86 and later · before 4.14.303
  • linux linux kernel4.19.7 and later · before 4.19.270
  • linux linux kernel4.20 and later · before 5.4.229
  • linux linux kernel5.5.0 and later · before 5.10.163
  • linux linux kernel5.11 and later · before 5.15.87
  • linux linux kernel5.16 and later · before 6.0.19
  • linux linux kernel6.1 and later · before 6.1.5
  • linux linux kernel3.16.68 and later · before 3.17
  • netapp active iq unified managerall versions
  • netapp h300s firmwareall versions
  • netapp h410c firmwareall versions
  • netapp h410s firmwareall versions
  • netapp h500s firmwareall versions
  • netapp h700s firmwareall versions

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Google). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux Kernel

    • 9137bb27e60e and later · before a664ec9158eeddd75121d39c9a0758016097fa96affected · git

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:10linuxbefore 4.19.282-14.19.282-1
Debian:10linux-5.10before 5.10.178-3~deb10u15.10.178-3~deb10u1
Debian:12linuxbefore 6.1.7-16.1.7-1
openSUSE:Leap 15.4dtb-aarch64before 5.3.18-150300.59.115.15.3.18-150300.59.115.1
openSUSE:Leap 15.4dtb-aarch64before 5.14.21-150400.24.55.15.14.21-150400.24.55.1
openSUSE:Leap 15.4kernel-debugbefore 5.14.21-150400.24.55.35.14.21-150400.24.55.3
openSUSE:Leap 15.4kernel-debugbefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2
openSUSE:Leap 15.4kernel-kvmsmallbefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2
openSUSE:Leap 15.4kernel-kvmsmallbefore 5.14.21-150400.24.55.35.14.21-150400.24.55.3
openSUSE:Leap 15.4kernel-obs-qabefore 5.14.21-150400.24.55.15.14.21-150400.24.55.1
openSUSE:Leap 15.4kernel-vanillabefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2
openSUSE:Leap 15.5dtb-aarch64before 5.14.21-150500.55.7.15.14.21-150500.55.7.1
openSUSE:Leap 15.5kernel-debugbefore 5.14.21-150500.55.7.15.14.21-150500.55.7.1
openSUSE:Leap 15.5kernel-kvmsmallbefore 5.14.21-150500.55.7.15.14.21-150500.55.7.1
openSUSE:Leap 15.5kernel-obs-qabefore 5.14.21-150500.55.7.15.14.21-150500.55.7.1
openSUSE:Tumbleweedkernel-sourcebefore 6.1.12-1.16.1.12-1.1
SUSE:Linux Enterprise High Availability Extension 12 SP5kernel-defaultbefore 4.12.14-122.150.14.12.14-122.150.1
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSSkernel-docsbefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSSkernel-docsbefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSSkernel-obs-buildbefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSSkernel-obs-buildbefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSSkernel-sourcebefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSSkernel-sourcebefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSSkernel-symsbefore 4.12.14-150100.197.137.24.12.14-150100.197.137.2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now
  • CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
    83Now

Published before and after this one in the same product

  • ← EarlierCVE-2023-2019Apr 24, 2023 · A flaw was found in the Linux kernel's netdevsim device driver, within the scheduling of events.
    17Monitor
  • ← EarlierCVE-2023-2007Apr 24, 2023 · The specific flaw exists within the DPT I2O Controller driver.
    31Monitor
  • Later →CVE-2023-2269Apr 25, 2023 · A denial of service problem was found, due to a possible recursive locking scenario, resulting in a deadlock in table_clear in drivers/md/dm
    17Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux Kernela664ec9158eeddd75121d39c9a0758016097fa96Vendor (CNA)
debian:linux6.1.7-1 · Debian:12Package registry (OSV)
debian:linux-5.105.10.178-3~deb10u1 · Debian:10Package registry (OSV)
opensuse:kernel-rt5.14.21-150400.15.11.1 · openSUSE:Leap Micro 5.3Package registry (OSV)
opensuse:kernel-rt_debug5.14.21-150400.15.11.1 · openSUSE:Leap 15.4Package registry (OSV)
opensuse:kernel-source-rt5.14.21-150400.15.11.1 · openSUSE:Leap 15.4Package registry (OSV)
opensuse:kernel-syms-rt5.14.21-150400.15.11.1 · openSUSE:Leap 15.4Package registry (OSV)
suse:kernel-azure4.12.14-16.124.1 · SUSE:Linux Enterprise Server 12 SP5Package registry (OSV)
suse:kernel-default4.12.14-150100.197.137.2 · SUSE:Linux Enterprise Live Patching 15 SP1Package registry (OSV)
suse:kernel-docs4.12.14-150100.197.137.2 · SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSSPackage registry (OSV)
suse:kernel-livepatch-SLE15-SP1_Update_381-150100.3.3.2 · SUSE:Linux Enterprise Live Patching 15 SP1Package registry (OSV)
suse:kernel-livepatch-SLE15-SP4-RT_Update_31-150400.1.3.1 · SUSE:Linux Enterprise Live Patching 15 SP4Package registry (OSV)
suse:kernel-rt4.12.14-10.115.1 · SUSE:Linux Enterprise Real Time 12 SP5Package registry (OSV)
suse:kernel-rt5.14.21-150400.15.11.1 · SUSE:Linux Enterprise Micro 5.3Package registry (OSV)
suse:kernel-rt_debug4.12.14-10.115.1 · SUSE:Linux Enterprise Real Time 12 SP5Package registry (OSV)
suse:kernel-rt_debug5.14.21-150400.15.11.1 · SUSE:Real Time Module 15 SP4Package registry (OSV)
suse:kernel-source-azure4.12.14-16.124.1 · SUSE:Linux Enterprise Server 12 SP5Package registry (OSV)
suse:kernel-source-rt4.12.14-10.115.1 · SUSE:Linux Enterprise Real Time 12 SP5Package registry (OSV)
suse:kernel-source-rt5.14.21-150400.15.11.1 · SUSE:Real Time Module 15 SP4Package registry (OSV)
suse:kernel-syms-azure4.12.14-16.124.1 · SUSE:Linux Enterprise Server 12 SP5Package registry (OSV)
suse:kernel-syms-rt4.12.14-10.115.1 · SUSE:Linux Enterprise Real Time 12 SP5Package registry (OSV)
suse:kernel-syms-rt5.14.21-150400.15.11.1 · SUSE:Real Time Module 15 SP4Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×2

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:32023-02-04
Proof-of-concept repository on GitHubstars:142023-02-07

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-81 d
  2. Published
  3. TodayOct 22, 2026+1275 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-610 · Externally Controlled Reference to a Resource in Another Sphere

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records