CVE-2021-23909Network attack vector

Remote code execution on SH2 MCU

Published May 13, 2021 · Updated Aug 3, 2024

Remote code execution in HERMES 2.1 in Mercedes-Benz MBUX Infotainment System allows remote attackers to execute code on the SH2 MCU. The published record identifies the SH2 MCU as the execution locus but does not disclose the triggering operation or input flaw. Exploitation requires network access to the vehicle system, and resulting code execution can compromise MCU integrity and availability.

CVSS severity6.3
Medium
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

Remote code execution in HERMES 2.1 in Mercedes-Benz MBUX Infotainment System allows remote attackers to execute code on the SH2 MCU. The published record identifies the SH2 MCU as the execution locus but does not disclose the triggering operation or input flaw. Exploitation requires network access to the vehicle system, and resulting code execution can compromise MCU integrity and availability.

The record

CVE
CVE-2021-23909
Published
May 13, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.3MITRE CNACVSS:3.1/AV:L/AC:L/PR:H/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.

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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