CVE-2023-4856Network attack vector

Authenticated command execution via format string

Published Apr 15, 2024 · Updated Aug 2, 2024

Format string injection in Lenovo SMM, SMM2, and FPC firmware allows remote authenticated users to execute arbitrary commands via an API endpoint. Lenovo has not disclosed the endpoint or the operation that treats attacker-controlled input as a format string. Network access and valid credentials are required, and successful exploitation executes commands on the enclosure management controller.

CVSS severity8.8
High
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Format string injection in Lenovo SMM, SMM2, and FPC firmware allows remote authenticated users to execute arbitrary commands via an API endpoint. Lenovo has not disclosed the endpoint or the operation that treats attacker-controlled input as a format string. Network access and valid credentials are required, and successful exploitation executes commands on the enclosure management controller.

The record

CVE
CVE-2023-4856
Published
Apr 15, 2024
Updated
Aug 2, 2024
Vendor
Lenovo
Product
Lenovo System Management Module Firmware
Classifications
CWE-78, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 15, 2024CVE 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?

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

  1. Affected versionversion=1.24 <tesm40b-1.27

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Lenovo · Lenovo System Management Module Firmwareversion=1.24 <tesm40b-1.27
Lenovo · Lenovo Fan/Power Controller Module Firmwareversion=0 <fhet62a-3.50

Published CVSS scores

8.8Lenovo Group Ltd.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

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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