CVE-2023-4135

Guest-to-host heap disclosure via unchecked FDP offset

Published Aug 4, 2023 · Updated Aug 2, 2024

Out-of-bounds read in QEMU's virtual NVMe device in Fedora Linux 38 allows guest OS users to disclose host heap data through an FDP log request. The nvme_fdp_events() path uses a guest-supplied log-page offset to derive a heap pointer and copy data without first checking the offset against the generated event-log size. Exploitation requires guest access to a virtual NVMe controller configured with Flexible Data Placement enabled, and it exposes heap contents from the host QEMU process without enabling data modification.

CVSS severity6.5
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in QEMU's virtual NVMe device in Fedora Linux 38 allows guest OS users to disclose host heap data through an FDP log request. The nvme_fdp_events() path uses a guest-supplied log-page offset to derive a heap pointer and copy data without first checking the offset against the generated event-log size. Exploitation requires guest access to a virtual NVMe controller configured with Flexible Data Placement enabled, and it exposes heap contents from the host QEMU process without enabling data modification.

The record

CVE
CVE-2023-4135
Published
Aug 4, 2023
Updated
Aug 2, 2024
Vendor
Fedora Project
Product
Fedora Linux
Classifications
CWE-125, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Fedora Project · Fedora LinuxAffected versions are unavailable in this record.

Published CVSS scores

6.5Red Hat, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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