CVE-2021-20094Public exploitNetwork attack vector

Remote service crash via invalid virtual call

Published Jun 16, 2021 · Updated Aug 3, 2024

Denial of service in the WIBU-SYSTEMS AG CodeMeter Runtime CmWAN server before 7.21a allows remote attackers to crash the service. A crafted unencrypted HTTP(S) message beginning with the CmWAN marker reaches an invalid C++ virtual-function pointer and terminates the process. Direct access to port 22351 permits an unauthenticated attack, while the standard reverse-proxy deployment requires authentication and CmWAN is disabled by default.

CVSS severity7.5
High
EPSS probability4.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the WIBU-SYSTEMS AG CodeMeter Runtime CmWAN server before 7.21a allows remote attackers to crash the service. A crafted unencrypted HTTP(S) message beginning with the CmWAN marker reaches an invalid C++ virtual-function pointer and terminates the process. Direct access to port 22351 permits an unauthenticated attack, while the standard reverse-proxy deployment requires authentication and CmWAN is disabled by default.

The record

CVE
CVE-2021-20094
Published
Jun 16, 2021
Updated
Aug 3, 2024
Vendor
WIBU-SYSTEMS AG
Product
CodeMeter Runtime
Classifications
CWE-125, CWE-126, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 16, 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?

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

  1. Affected versionversion=< 7.21a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WIBU-SYSTEMS AG · CodeMeter Runtimeversion=< 7.21a

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5WIBU-SYSTEMS AGCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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 exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
CWE-126Buffer Over-read
T1499.004Application or System Exploitation

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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