CVE-2021-27245

HIGHCVSS 8.1/10EPSS 3.21%

Last modified

CVE-2021-27245 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. 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. EPSS estimates a 3.21% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
8.1/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
3.21%

86.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
Tp-LinkArcher A7 Firmware< c7\(us\)_v5_210125
Tp-LinkArcher A7 Firmware< a7\(us\)_v5_200220

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-27245?
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.
How severe is CVE-2021-27245?
CVE-2021-27245 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 3.21% probability of exploitation in the next 30 days.
How do I fix CVE-2021-27245?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-27245?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST