What is the CVSS score of CVE-2021-27245?

CVE-2021-27245 has a CVSS 3.1 base score of 8.1 (High). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 3.2%.

Archer A7 Firmware CVE-2021-27245

HIGH

Protection Mechanism Failure (CWE-693)

2021-03-29 zdi-disclosures@trendmicro.com

TP-Link Authentication Bypass Archer A7 Firmware

8.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.1 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Mar 29, 2021 - 21:15 nvd

HIGH 8.1

DescriptionNVD

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.

AnalysisAI

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. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Technical ContextAI

This vulnerability is classified under CWE-693. 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. Affected products include: Tp-Link Archer A7 Firmware.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.