CVE-2021-20093Network attack vector

Heap disclosure or server crash via copy length

Published Jun 16, 2021 · Updated Aug 3, 2024

Buffer over-read in CodeMeter Runtime before 7.21a allows remote attackers to disclose heap memory or crash the server. The network server copies from a heap buffer into its response buffer using a client-controlled length in a crafted TCP packet. The unauthenticated service can therefore expose process memory or interrupt CodeMeter.exe when network-server mode is enabled.

CVSS severity9.1
Critical
EPSS probability33.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer over-read in CodeMeter Runtime before 7.21a allows remote attackers to disclose heap memory or crash the server. The network server copies from a heap buffer into its response buffer using a client-controlled length in a crafted TCP packet. The unauthenticated service can therefore expose process memory or interrupt CodeMeter.exe when network-server mode is enabled.

The record

CVE
CVE-2021-20093
Published
Jun 16, 2021
Updated
Aug 3, 2024
Vendor
WIBU-SYSTEMS AG
Product
CodeMeter Runtime
Classifications
CWE-125, CWE-126, T1499
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

6.4NVDAV:N/AC:L/Au:N/C:P/I:N/A:P
9.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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-125Out-of-bounds Read
CWE-126Out-of-bounds Read
T1499Endpoint Denial of Service

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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