CVE-2021-27245 json
This vulnerability allows a firewall bypass on affected installations of TP-Link Archer A7 prior to Archer C7(US)_V5_210125 and Archer A7(U…
published 2021-03-29 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-14010
- cvss
- 8.1
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 3.3%
- EPSS 3.3% chance of exploitation in 30 days, percentile 88%
- public exploits
- 0
- none known
Summary
This vulnerability allows a firewall bypass on affected installations of TP-Link Archer A7 prior to Archer C7(US)_V5_210125 and Archer A7(US)_V5_200220 AC1750 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of IPv6 connections. The issue results from the lack of proper filtering of IPv6 SSH connections. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of root. Was ZDI-CAN-12309.
Patch / fix
- tp-link archer_a7_firmware a7\(us\)_v5_200220, c7\(us\)_v5_210125
Exploit prediction
3.33% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 8.1 | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 9.3 | AV:N/AC:M/Au:N/C:C/I:C/A:C |
Affected products
- TP-Link Archer A7
Classification
- Weakness
-
- CWE-693 Protection Mechanism Failure
References
-
zerodayinitiative.com
/advisories/ZDI-21-214/
third-party-advisory, vdb-entry
Sources
- CVE List CVE-2021-27245
- NVD CVE-2021-27245
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