8.1
HIGH
CVE-2021-27245
"TP-Link Archer A7/Archer C7 IPv6 SSH Connection Filtering Vulnerability"
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.

INFO

Published Date :

March 29, 2021, 9:15 p.m.

Last Modified :

April 1, 2021, 6:46 p.m.

Remotely Exploitable :

Yes !

Impact Score :

5.9

Exploitability Score :

2.2
Public PoC/Exploit Available at Github

CVE-2021-27245 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2021-27245 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Tp-link archer_a7_firmware
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-27245.

URL Resource
https://www.zerodayinitiative.com/advisories/ZDI-21-214/ Third Party Advisory VDB Entry

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Repository that tracks public exploits, vulnerabilities and advisories that I [co-]discovered or [co-]authored.

Ruby Shell Python

Updated: 2 months, 4 weeks ago
108 stars 20 fork 20 watcher
Born at : April 8, 2020, 6:11 p.m. This repo has been linked 32 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-27245 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-27245 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Initial Analysis by [email protected]

    Apr. 01, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:M/Au:N/C:C/I:C/A:C)
    Added CVSS V3.1 NIST AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://www.zerodayinitiative.com/advisories/ZDI-21-214/ No Types Assigned https://www.zerodayinitiative.com/advisories/ZDI-21-214/ Third Party Advisory, VDB Entry
    Added CPE Configuration AND OR *cpe:2.3:o:tp-link:archer_a7_firmware:*:*:*:*:*:*:*:* versions up to (excluding) c7\(us\)_v5_210125 OR cpe:2.3:h:tp-link:archer_a7:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:tp-link:archer_a7_firmware:*:*:*:*:*:*:*:* versions up to (excluding) a7\(us\)_v5_200220 OR cpe:2.3:h:tp-link:archer_a7:-:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Mar. 29, 2021

    Action Type Old Value New Value
    Changed 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. 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.
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-27245 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-27245 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.53 }} 0.27%

score

0.74595

percentile

CVSS31 - Vulnerability Scoring System
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