CVE-2025-12259: TOTOLINK A3300R · Stack-based Buffer Overflow
Affects TOTOLINK A3300RSource CVE Database V5
Not known to be exploited · CVSS 8.7 High.
Data as of 26 Oct 2026, 08:30 UTC
- EPSS
- 1.0% chance of exploitation in 30 days – higher than 63% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS: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:PExploitation evidence
Disclosed: evidence found.
CVE published 27 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
AI-suggested
To mitigate CVE-2025-12259, organizations should immediately identify all TOTOLINK A3300R devices running firmware version 17.0.0cu.557_B20221024 or earlier. 2) Restrict network access to the router's management interface using firewall rules or network segmentation, allowing only trusted internal IP addresses. 3) Monitor network traffic for unusual POST requests targeting /cgi-bin/cstecgi.cgi, especially those containing the recHour parameter, to detect potential exploitation attempts. 4) If possible, downgrade or upgrade firmware to a version confirmed to be free of this vulnerability once released by the vendor. 5) Employ intrusion detection/prevention systems (IDS/IPS) with signatures targeting this exploit to block or alert on malicious activity. 6) Maintain strict network hygiene and ensure that routers are not directly exposed to untrusted networks without additional protective layers. 7) Engage with TOTOLINK support channels to obtain updates or patches as soon as they become available. These targeted mitigations go beyond generic advice by focusing on limiting attack surface and early detection specific to this vulnerability's exploitation vector.
Description
A flaw has been found in TOTOLINK A3300R 17.0.0cu.557_B20221024. The affected element is the function setScheduleCfg of the file /cgi-bin/cstecgi.cgi of the component POST Parameter Handler. This manipulation of the argument recHour causes stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been published and may be used.