CVE-2025-9791 Tenda AC20 fromAdvSetMacMtuWan stack-based overflow
A stack-based buffer overflow in the Tenda AC20 router allows remote attackers to execute arbitrary code or cause a denial of service via the wanMTU argument.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-9791?
CVE-2025-9791 is a high-severity memory corruption vulnerability in Tenda AC20, published on 1 Sep 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A weakness has been identified in Tenda AC20 16.03.08.05. This vulnerability affects unknown code of the file /goform/fromAdvSetMacMtuWan. This manipulation of the argument wanMTU causes stack-based buffer overflow. Remote exploitation of the attack is possible. The exploit has been made available to the public and could be exploited.
Which versions are affected by CVE-2025-9791?
It affects 1 product.
Products include Tenda Ac20 Firmware.
How do I fix CVE-2025-9791?
No fix has been published for CVE-2025-9791 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-9791 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-9791 exists.
Other vulnerabilities in Tenda AC20
- CVE-2025-15356 Tenda AC20 PowerSaveSet sscanf buffer overflow
- CVE-2025-14654 Tenda AC20 httpd setPptpUserList formSetPPTPUserList stack-based overflow
- CVE-2025-14655 Tenda AC20 httpd SetSysAutoRebbotCfg formSetRebootTimer stack-based overflow
- CVE-2025-14656 Tenda AC20 openSchedWifi httpd buffer overflow
- CVE-2025-13258 Tenda AC20 WifiExtraSet buffer overflow
Sources
Also known as GHSA-6x7v-g88f-587h.