CVE-2025-7912Public exploitNetwork attack vector

Remote code execution via unchecked MQTT sprintf

Published Jul 20, 2025 · Updated Jul 21, 2025

Buffer overflow in the MQTT service in TOTOLINK T6 4.1.5cu.748_B20211015 allows remote authenticated users to execute code via crafted packets. The recvSlaveUpgstatus function passes the packet-controlled ip value to sprintf without checking its length before copying it into the 68-byte s buffer. Successful exploitation through the TCP port 1883 listener can take control of the router without user interaction.

CVSS severity8.8
High
EPSS probability1.04%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in the MQTT service in TOTOLINK T6 4.1.5cu.748_B20211015 allows remote authenticated users to execute code via crafted packets. The recvSlaveUpgstatus function passes the packet-controlled ip value to sprintf without checking its length before copying it into the 68-byte s buffer. Successful exploitation through the TCP port 1883 listener can take control of the router without user interaction.

The record

CVE
CVE-2025-7912
Published
Jul 20, 2025
Updated
Jul 21, 2025
Vendor
TOTOLINK
Product
T6
Classifications
CWE-120, CWE-119, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 20, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 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=4.1.5cu.748_B20211015

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

TOTOLINK · T6version=4.1.5cu.748_B20211015

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
9.0VulDBAV: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-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
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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