Buffer overflow in Tenda Ac20
CVE-2025-9791
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.009 (56.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.009 · change: +0.000
Affected products
- Tenda Ac20 — versions 16.03.08.05
- Tenda Ac20 Firmware — versions 16.03.08.5
Weakness classification (CWE)
Public proof-of-concept exploits
References
- vuldb.com/ (technical-description, VDB Entry, Third Party Advisory, vdb-entry)
- vuldb.com/ (signature, Permissions Required, permissions-required, VDB Entry)
- vuldb.com/ (VDB Entry, Third Party Advisory, third-party-advisory)
- github.com/Cpppq43/Tenda/blob/main/Tenda_AC20_V16.03.08.05.md (related, Exploit, Third Party Advisory)
- github.com/Cpppq43/Tenda/blob/main/Tenda_AC20_V16.03.08.05.md (Exploit, Third Party Advisory, exploit)
- www.tenda.com.cn/ (Product, product)
Frequently asked questions
- What is CVE-2025-9791?
- CVE-2025-9791 is a high-severity vulnerability in Tenda Ac20, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.8/10. Published 2025-09-01.
- How severe is CVE-2025-9791?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2025-9791 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.