CVE-2021-23907Public exploit

Physically proximate code execution via unchecked counts

Published May 13, 2021 · Updated Aug 3, 2024

Heap overflow in Mercedes-Benz MBUX Headunit NTG6 through 2021 allows physically proximate attackers to execute code via HiQnet. The MultiSvGet and GetAttributes constructors trust payload counts when copying IDs into fixed-size heap buffers, while MultiSvSet uses its count to read and write beyond fixed arrays. Exploitation requires physical access to reach the head-unit intranet and a crafted HiQnet message; successful corruption permits arbitrary code execution in the head unit.

CVSS severity2.9
Low
EPSS probability2.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap overflow in Mercedes-Benz MBUX Headunit NTG6 through 2021 allows physically proximate attackers to execute code via HiQnet. The MultiSvGet and GetAttributes constructors trust payload counts when copying IDs into fixed-size heap buffers, while MultiSvSet uses its count to read and write beyond fixed arrays. Exploitation requires physical access to reach the head-unit intranet and a crafted HiQnet message; successful corruption permits arbitrary code execution in the head unit.

The record

CVE
CVE-2021-23907
Published
May 13, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
Unavailable
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
2.9MITRE CorporationCVSS:3.1/AC:H/AV:P/A:N/C:L/I:L/PR:N/S:U/UI:R

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 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 exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

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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