CVE-2021-34753: firepower threat Access Control Flaw

Description

A vulnerability in the payload inspection for Ethernet Industrial Protocol (ENIP) traffic for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured rules for ENIP traffic. This vulnerability is due to incomplete processing during deep packet inspection for ENIP packets. An attacker could exploit this vulnerability by sending a crafted ENIP packet to the targeted interface. A successful exploit could allow the attacker to bypass configured access control and intrusion policies that should trigger and drop for the ENIP packet.

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CVSS v3.1 Score

5.8

MEDIUM

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

Weakness Type (CWE)

CWE-284 CWE-284

Affected Products

Vendor	Product	Versions
cisco	firepower_threat_defense_software	< 6.4.0.13
cisco	firepower_threat_defense_software	6.5.0 — 6.6.5.1
cisco	firepower_threat_defense_software	6.7.0 — 6.7.0.3
cisco	firepower_threat_defense_software	All

References

Advisories & Patches

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-enip-bypass-eFsxd8KP

Frequently Asked Questions

What is CVE-2021-34753? +

A vulnerability in the payload inspection for Ethernet Industrial Protocol (ENIP) traffic for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured rules for ENIP traffic. This vulnerability is due to incomplete processing during deep packet inspection for ENIP packets. An attacker could exploit this vulnerability by sending a crafted ENIP packet to the targeted interface. A successful exploit could allow the attacker to bypass configured access control and intrusion policies that should trigger and drop for the ENIP packet. It has a CVSS v3.1 base score of 5.8 (MEDIUM).

How severe is CVE-2021-34753? +

CVE-2021-34753 has a CVSS v3.1 score of 5.8 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2021-34753? +

CVE-2021-34753 affects products from cisco, specifically: firepower_threat_defense_software. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2021-34753? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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