Critical severity · published Oct 27, 2025
CVE-2025-12240
TOTOLINK A3300R cstecgi.cgi setDmzCfg buffer overflow
9.8
CVSS
0.8%
EPSS
No
On KEV
Description
A security vulnerability has been detected in TOTOLINK A3300R 17.0.0cu.557_B20221024. This affects the function setDmzCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument ip leads to buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed publicly and may be used.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 58% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
A3
A3300R · TOTOLINK
17.0.0cu.557_B20221024 · source: vendor
AF
A3300r Firmware · Totolink
17.0.0cu.557_b20221024 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-12240
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-12240
Exploit
https://github.com/noahze01/IoT-vulnerable/blob/main/TOTOLink/A3300R/setDmzCfg.md
Permissions Required
https://vuldb.com/?ctiid.329910
Third Party Advisory
https://vuldb.com/?id.329910
Third Party Advisory
https://vuldb.com/?submit.673722
Product
https://www.totolink.net/
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