CVE-2025-13446: Tenda AC21 · Stack-based Buffer Overflow
Affects Tenda AC21Source CVE Database V5
Not known to be exploited · CVSS 8.7 High.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 4.2% chance of exploitation in 30 days – higher than 90% 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:PExploitation evidence
Disclosed: evidence found.
CVE published 20 Nov 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 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Tenda AC21 | Affected
| Fixed in– |
AI-suggested
Given the absence of official patches at the time of disclosure, organizations should implement immediate mitigations to reduce risk. Network administrators should isolate Tenda AC21 devices from untrusted networks, restricting access to the management interface, especially the /goform/SetSysTimeCfg endpoint, via firewall rules or network segmentation. Disabling remote management features or restricting them to trusted IP addresses can limit exposure. Monitoring network traffic for unusual requests targeting the vulnerable endpoint can help detect exploitation attempts. Organizations should maintain up-to-date inventories of affected devices and prioritize firmware updates once patches become available from Tenda. Employing network intrusion detection/prevention systems (IDS/IPS) with signatures targeting this vulnerability can provide additional defense. Users should also consider replacing vulnerable devices if patches are delayed or unavailable. Finally, raising user awareness about the risks and encouraging secure configuration practices will help mitigate exploitation.
Description
A vulnerability has been found in Tenda AC21 16.03.08.16. This vulnerability affects unknown code of the file /goform/SetSysTimeCfg. The manipulation of the argument timeZone/time leads to stack-based buffer overflow. The attack is possible to be carried out remotely. The exploit has been disclosed to the public and may be used.
References
- vuldb.com (opens in a new tab)
- vuldb.com (opens in a new tab)
- vuldb.com (opens in a new tab)
- vuldb.com (opens in a new tab)
- github.com/Madgeaaaaa/MY_VULN_2/blob/main/Tenda/VULN8.md (opens in a new tab)
- github.com/Madgeaaaaa/MY_VULN_2/blob/main/Tenda/VULN9.md (opens in a new tab)
- tenda.com.cn (opens in a new tab)