CVE-2025-12258: 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:XExploitation 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-2025-12258, organizations should immediately identify all TOTOLINK A3300R devices running the vulnerable firmware version 17.0.0cu.557_B20221024. Since no official patches are currently available, temporary mitigations include restricting access to the router's management interface by implementing network segmentation and firewall rules that block unsolicited inbound traffic to the /cgi-bin/cstecgi.cg endpoint. Disabling remote management features or restricting them to trusted IP addresses can reduce exposure. Monitoring network traffic for unusual POST requests targeting the 'opmode' parameter may help detect exploitation attempts. Organizations should engage with TOTOLINK support for firmware updates and apply patches promptly once released. Additionally, consider deploying intrusion detection/prevention systems (IDS/IPS) with signatures targeting this vulnerability. Regularly auditing router configurations and maintaining an inventory of network devices will enhance readiness for future vulnerabilities.
Description
A vulnerability was detected in TOTOLINK A3300R 17.0.0cu.557_B20221024. Impacted is the function setOpModeCfg of the file /cgi-bin/cstecgi.cg of the component POST Parameter Handler. The manipulation of the argument opmode results in stack-based buffer overflow. The attack may be performed from remote.