CVE-2021-44467Network attack vector

Unauthenticated session termination via unchecked QSESSIONID

Published Oct 24, 2022 · Updated May 7, 2025

Broken access control in Lanner IAC-AST2500A firmware 1.10.0 allows remote attackers to terminate other users' active sessions. KillDupUsr_func handles a POST to /api/KillDupUsr but does not verify its QSESSIONID cookie before ending the named user's sessions. Exploitation requires correctly guessing the input parameter; repeated requests deny access to the device without disclosing or modifying data.

CVSS severity5.3
Medium
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Broken access control in Lanner IAC-AST2500A firmware 1.10.0 allows remote attackers to terminate other users' active sessions. KillDupUsr_func handles a POST to /api/KillDupUsr but does not verify its QSESSIONID cookie before ending the named user's sessions. Exploitation requires correctly guessing the input parameter; repeated requests deny access to the device without disclosing or modifying data.

The record

CVE
CVE-2021-44467
Published
Oct 24, 2022
Updated
May 7, 2025
Vendor
Lanner Electronics Inc
Product
IAC-AST2500A
Classifications
CWE-284, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 24, 2022CVE publishedPublication date reported by the CVE source.
  2. May 7, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=1.10.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Lanner Electronics Inc · IAC-AST2500Aversion=1.10.0

Published CVSS scores

5.3Nozomi Networks Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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.

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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