CVE-2025-12240Public exploitNetwork attack vector

Stack overflow via unchecked DMZ host length

Published Oct 27, 2025 · Updated Oct 27, 2025

Stack buffer overflow in TOTOLINK A3300R 17.0.0cu.557_B20221024 allows remote authenticated users to corrupt memory via DMZ settings. The setDmzCfg handler in /cgi-bin/cstecgi.cgi writes the ip parameter to dmz.host without a length check, and getDmzCfg later copies the stored value onto the stack without bounds checking. A valid session and enable=1 are required; the published proof of concept triggers the overflow, but no further consequence is demonstrated.

CVSS severity8.8
High
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in TOTOLINK A3300R 17.0.0cu.557_B20221024 allows remote authenticated users to corrupt memory via DMZ settings. The setDmzCfg handler in /cgi-bin/cstecgi.cgi writes the ip parameter to dmz.host without a length check, and getDmzCfg later copies the stored value onto the stack without bounds checking. A valid session and enable=1 are required; the published proof of concept triggers the overflow, but no further consequence is demonstrated.

The record

CVE
CVE-2025-12240
Published
Oct 27, 2025
Updated
Oct 27, 2025
Vendor
TOTOLINK
Product
A3300R
Classifications
CWE-119, CWE-120
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 27, 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=17.0.0cu.557_B20221024

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

TOTOLINK · A3300Rversion=17.0.0cu.557_B20221024

Published CVSS scores

7.4VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/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 exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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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