CVE-2021-26731Network attack vector

Root code execution via authenticated user modification

Published Oct 24, 2022 · Updated May 7, 2025

Command injection and stack-based buffer overflows in Lanner IAC-AST2500A firmware 1.10.0 allow remote authenticated users to execute code. The flaws reside in modifyUserb_func within spx_restservice, but Nozomi has not published the unsafe input operations or affected parameters. Access to the authenticated user-modification path is required, and successful exploitation executes with root privileges on the BMC.

CVSS severity9.1
Critical
EPSS probability2.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection and stack-based buffer overflows in Lanner IAC-AST2500A firmware 1.10.0 allow remote authenticated users to execute code. The flaws reside in modifyUserb_func within spx_restservice, but Nozomi has not published the unsafe input operations or affected parameters. Access to the authenticated user-modification path is required, and successful exploitation executes with root privileges on the BMC.

The record

CVE
CVE-2021-26731
Published
Oct 24, 2022
Updated
May 7, 2025
Vendor
Lanner Electronics Inc
Product
IAC-AST2500A
Classifications
CWE-787, CWE-77, CWE-121, CWE-94, T1190
Attack vector
network
Privileges
authenticated

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?

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

  1. Affected versionversion=1.10.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Lanner Electronics Inc · IAC-AST2500Aversion=1.10.0

Published CVSS scores

9.1Nozomi NetworksCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
CWE-121Stack-based Buffer Overflow
CWE-94Improper Control of Generation of Code ('Code Injection')
T1190Exploit Public-Facing Application

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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