CVE-2021-23908Known exploitationPublic exploit

Code execution via HiQnet type confusion

Published May 13, 2021 · Updated Aug 3, 2024

Type confusion in Mercedes-Benz MBUX Headunit NTG6 through 2021 allows physically proximate attackers to execute arbitrary code. MultiSvSetAttributes trusts a payload-selected type, casts an existing CSvClassOnOffUByte object as CSvLong64 or CSvBlock, and writes beyond it into adjacent structures. Reaching the HiQnet TCP or UDP service requires physical proximity and user interaction; successful corruption enables memory disclosure and control-flow hijacking in the head unit.

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

What happened

Type confusion in Mercedes-Benz MBUX Headunit NTG6 through 2021 allows physically proximate attackers to execute arbitrary code. MultiSvSetAttributes trusts a payload-selected type, casts an existing CSvClassOnOffUByte object as CSvLong64 or CSvBlock, and writes beyond it into adjacent structures. Reaching the HiQnet TCP or UDP service requires physical proximity and user interaction; successful corruption enables memory disclosure and control-flow hijacking in the head unit.

The record

CVE
CVE-2021-23908
Published
May 13, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-843, T1203
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

2.9MITRECVSS:3.1/AC:H/AV:P/A:N/C:L/I:L/PR:N/S:U/UI:R
7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
T1203Exploitation for Client Execution

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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