CVE-2023-4265

Memory corruption via unchecked USB buffer copies

Published Aug 12, 2023 · Updated Feb 13, 2025

Buffer overflows in Zephyr RTOS USB code before 3.4.0 allow physically proximate attackers to corrupt memory through crafted USB data. usb_dc_ep_write copies data_len bytes into a fixed 64-byte endpoint buffer, while handle_encapsulated_rsp copies buf->len bytes without checking destination capacity. Reachability requires attacker control of the copied data and length; the report does not establish whether corruption produces a crash or code execution.

CVSS severity6.4
Medium
EPSS probability0.82%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflows in Zephyr RTOS USB code before 3.4.0 allow physically proximate attackers to corrupt memory through crafted USB data. usb_dc_ep_write copies data_len bytes into a fixed 64-byte endpoint buffer, while handle_encapsulated_rsp copies buf->len bytes without checking destination capacity. Reachability requires attacker control of the copied data and length; the report does not establish whether corruption produces a crash or code execution.

The record

CVE
CVE-2023-4265
Published
Aug 12, 2023
Updated
Feb 13, 2025
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-120, CAPEC-100
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=* <=3.3

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=* <=3.3

Published CVSS scores

6.8NIST NVDCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.4Zephyr ProjectCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H

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)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CAPEC-100Overflow Buffers

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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