TOTOLINK CA300-PoE cstecgi.cgi setLanConfig buffer overflow

Summary

A vulnerability was identified in TOTOLINK CA300-PoE 6.2c.884. The affected element is the function setLanConfig of the file /cgi-bin/cstecgi.cgi. Such manipulation of the argument lanDns/lanSecDns/langType leads to buffer overflow. It is possible to launch the attack remotely. The exploit is publicly available and might be used.

Remediation

1. Inventory every TOTOLINK CA300-PoE deployment, including staging.
2. No fixed version appears in the public sources yet. Check the references below and the vendor directly.

References

• Advisoryhttps://vuldb.com/cve/CVE-2026-123958
• Advisoryhttps://vuldb.com/submit/1033673
• Referencehttps://vuldb.com/vuln/432021
• Referencehttps://vuldb.com/vuln/432021/cti
• Referencehttps://lavender-bicycle-a5a.notion.site/TOTOLINK-CA300-PoE-setLanConfig-3f953a41781f8029941cd21d2cc16db0?source=copy_link
• Referencehttps://www.totolink.net/