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CVE-2021-34753

MEDIUMCVSS 5.3/10EPSS 0.65%

Last modified

CVE-2021-34753 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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. EPSS estimates a 0.65% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.3/10

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

EPSS Probability
0.65%

46.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoFirepower Threat Defense Software< 6.4.0.13
CiscoFirepower Threat Defense Software>= 6.5.0, < 6.6.5.1
CiscoFirepower Threat Defense Software>= 6.7.0, < 6.7.0.3
CiscoFirepower Threat Defense Software7.0.0

References

Timeline

Published
Last Modified
Status
Analyzed

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.
How severe is CVE-2021-34753?
CVE-2021-34753 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.65% probability of exploitation in the next 30 days.
How do I fix CVE-2021-34753?
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-2021-34753?

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

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Source: NVD / NIST