CVE-2023-40942Public exploitNetwork attack vector

Root shell via unchecked firewall setting copy

Published Sep 7, 2023 · Updated Sep 26, 2024

Stack overflow in Tenda AC9 Firmware V15.03.06.42_multi_TD01 allows remote authenticated users to execute code via firewallEn. The formSetFirewallCfg handler copies that user-controlled value with strcpy into the eight-byte firewall_buf stack array without enforcing an upper bound. The published request supplies a password cookie and reports root-shell access, although NVD assesses the flaw as requiring no privileges.

CVSS severity9.8
Critical
EPSS probability0.84%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack overflow in Tenda AC9 Firmware V15.03.06.42_multi_TD01 allows remote authenticated users to execute code via firewallEn. The formSetFirewallCfg handler copies that user-controlled value with strcpy into the eight-byte firewall_buf stack array without enforcing an upper bound. The published request supplies a password cookie and reports root-shell access, although NVD assesses the flaw as requiring no privileges.

The record

CVE
CVE-2023-40942
Published
Sep 7, 2023
Updated
Sep 26, 2024
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
Tenda AC9 Firmware
Classifications
CWE-787, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 7, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 26, 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=V15.03.06.42_multi_TD01

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · Tenda AC9 Firmwareversion=V15.03.06.42_multi_TD01

Published CVSS scores

9.8NVDCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1190Exploit Public-Facing Application

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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