CVE-2021-45769Public exploitNetwork attack vector

Server crash via unchecked ACSE message buffer

Published Jan 14, 2022 · Updated Aug 4, 2024

NULL pointer dereference in libiec61850 1.5.0 allows remote attackers to crash an IEC 61850 server via a crafted ACSE message. AcseConnection_parseMessage reads buffer[0] at src/mms/iso_acse/acse.c:429 without first establishing that the message buffer is non-NULL. An unauthenticated TCP connection to the listening server is sufficient, and exploitation terminates the hosting process without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability1.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in libiec61850 1.5.0 allows remote attackers to crash an IEC 61850 server via a crafted ACSE message. AcseConnection_parseMessage reads buffer[0] at src/mms/iso_acse/acse.c:429 without first establishing that the message buffer is non-NULL. An unauthenticated TCP connection to the listening server is sufficient, and exploitation terminates the hosting process without reported data disclosure or modification.

The record

CVE
CVE-2021-45769
Published
Jan 14, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDCVSS: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.

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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-476NULL Pointer Dereference
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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