CVE-2017-9139 — There is a stack-based buffer overflow on some Tenda routers (FH1202/F1202/F1200

There is a stack-based buffer overflow on some Tenda routers (FH1202/F1202/F1200: versions before 1.2.0.20). Crafted POST requests to an unspecified URL result in DoS, interrupting the HTTP service (used to login to the web UI of a router) for 1 to 2 seconds.

01What is this vulnerability?

There is a stack-based buffer overflow on some Tenda routers (FH1202/F1202/F1200: versions before 1.2.0.20). Crafted POST requests to an unspecified URL result in DoS, interrupting the HTTP service (used to login to the web UI of a router) for 1 to 2 seconds.

02Affected products

No structured affected-product list available — see references below for vendor advisories.

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2017-05-21T22:29:00.210
• Last modified: 2026-05-13T00:24:29.033

09References

• www.tendacn.com — http://www.tendacn.com/en/2017.html
• www.tendacn.com — http://www.tendacn.com/en/2017.html