HOMEVULNERABILITIESCVE-2021-23909
CRITICAL

CVE-2021-23909

CWE-787Published: May 13, 2021· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

An issue was discovered in HERMES 2.1 in the MBUX Infotainment System on Mercedes-Benz vehicles through 2021. The SH2 MCU allows remote code execution.

NVD Source

Technical Analysis

CVE-2021-23909 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

mercedes-benz8 product(s)
hermesa 220a 220 4matice 350e 350 4maticeqcgle 350gle 350 4matic
Source: NVD CPE · 8 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://keenlab.tencent.com/en/2021/05/12/Tencent-Security-Keen-Lab-Experimental-Security-Assessment-on-Mercedes-Benz-Cars/
ADVISORYhttps://keenlab.tencent.com/en/whitepapers/Mercedes_Benz_Security_Research_Report_Final.pdf
ADVISORYhttps://media.daimler.com/marsMediaSite/en/instance/ko.xhtml?oid=49946866
ADVISORYhttps://keenlab.tencent.com/en/2021/05/12/Tencent-Security-Keen-Lab-Experimental-Security-Assessment-on-Mercedes-Benz-Cars/
ADVISORYhttps://keenlab.tencent.com/en/whitepapers/Mercedes_Benz_Security_Research_Report_Final.pdf
ADVISORYhttps://media.daimler.com/marsMediaSite/en/instance/ko.xhtml?oid=49946866

All References (6)

→
https://keenlab.tencent.com/en/2021/05/12/Tencent-Security-Keen-Lab-Experimental-Security-Assessment-on-Mercedes-Benz-Cars/Third Party Advisory
→
https://keenlab.tencent.com/en/whitepapers/Mercedes_Benz_Security_Research_Report_Final.pdfExploit · Third Party Advisory
→
https://media.daimler.com/marsMediaSite/en/instance/ko.xhtml?oid=49946866Third Party Advisory
→
https://keenlab.tencent.com/en/2021/05/12/Tencent-Security-Keen-Lab-Experimental-Security-Assessment-on-Mercedes-Benz-Cars/Third Party Advisory
→
https://keenlab.tencent.com/en/whitepapers/Mercedes_Benz_Security_Research_Report_Final.pdfExploit · Third Party Advisory
→
https://media.daimler.com/marsMediaSite/en/instance/ko.xhtml?oid=49946866Third Party Advisory

Quick Facts

CVE IDCVE-2021-23909
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-787
CISA KEVNo
Affected1 vendor(s)
PublishedMay 13, 2021

Related CVEs (CWE-787)

CVE-2004-0978
10.0
CVE-2014-1478
10.0
CVE-2018-10718
10.0
CVE-2009-2466
10.0
CVE-2013-5610
10.0
CVE-2016-9343
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-23909 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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