CVE-2025-9091: Tenda AC20 · Hard-coded Credentials
Affects Tenda AC20Source CVE Database V5
Not known to be exploited · CVSS 2.0 Low.
Data as of 26 Oct 2026, 08:30 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:PExploitation evidence
Disclosed: evidence found.
CVE published 17 Aug 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 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Tenda AC20 | Affected
| Fixed in– |
AI-suggested
European organizations should implement network segmentation to limit local access to Tenda AC20 devices, ensuring that only trusted administrators and systems can communicate with the router's management interface. Physical security controls should be enforced to prevent unauthorized physical access to the devices. Monitoring network traffic for unusual authentication attempts or configuration changes on these routers can help detect exploitation attempts. Organizations should consider replacing or upgrading affected devices to newer firmware versions once patches become available or migrating to alternative hardware with better security postures. Additionally, disabling any unnecessary services or management interfaces on the router can reduce the attack surface. Regular audits of device configurations and credentials should be conducted to identify and remediate any use of default or hard-coded credentials.
Description
A security flaw has been discovered in Tenda AC20 16.03.08.12. Affected by this vulnerability is an unknown functionality of the file /etc_ro/shadow. The manipulation leads to hard-coded credentials. It is possible to launch the attack on the local host. The complexity of an attack is rather high. The exploitation appears to be difficult. 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)
- github.com/ZZ2266/.github.io/tree/main/AC20/hardcoded%20password/readme.md (opens in a new tab)
- github.com/ZZ2266/.github.io/blob/main/AC20/hardcoded%20password/readme.md (opens in a new tab)
- tenda.com.cn (opens in a new tab)
- github.com/ZZ2266/.github.io/blob/main/AC20/hardcoded%20password/readme.md (opens in a new tab)