Is CVE-2021-27245 in the CISA KEV catalog?

No. CVE-2021-27245 is not currently on the CISA Known Exploited Vulnerabilities list.

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

CVE-2021-27245 has a CVSS v3 base score of 8.1 (HIGH).

What is the EPSS score for CVE-2021-27245?

CVE-2021-27245 has an EPSS score of 3.21% (87th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-27245?

Upgrade archer a7 firmware to a7(us)_v5_200220 or later.

CVE & CISA-KEV Catalog

CVE-2021-27245

HIGHEPSS 87th pctl

8.1

CVSS v3

NVD

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.

CWE-693Protection Mechanism Failure

How to fix

Remediation Available

archer a7 firmwareNVD

Affected:< a7(us)_v5_200220Fixed in:a7(us)_v5_200220CVE-2021-27245derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

3.21%probability of exploitation in 30 days

87thpercentile

Elevated risk: more likely to be exploited than 87% of all known CVEs.

References

Third-Party Advisory1

zerodayinitiative.com

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.