CVE-2020-3533

What it is

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to restart unexpectedly. The vulnerability is due to a lack of sufficient memory management protections under heavy SNMP polling loads. An attacker could exploit this vulnerability by sending a high rate of SNMP requests to the SNMP daemon through the management interface on an affected device. A successful exploit could allow the attacker to cause the SNMP daemon process to consume a large amount of system memory over time, which could then lead to an unexpected device restart, causing a denial of service (DoS) condition. This vulnerability affects all versions of SNMP.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of service disruption.

Exploit odds

1.8% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2020-10-21 19:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-08-11 19:37 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.8% in the next 30 days (EPSS).
• Severity: 8.6 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2020-10-21 19:15 UTC

Last modified

2026-08-11 19:37 UTC

Exploit probability

1.8% · EPSS, next 30 days

Weakness

CWE-400 · Uncontrolled resource consumption

Record status

Modified

Affected

• Cisco Secure Firewall Threat Defense < 6.3.0.6
• Cisco Secure Firewall Threat Defense < 6.4.0.10
• Cisco Secure Firewall Threat Defense < 6.5.0.5
• Cisco Secure Firewall Threat Defense < 6.6.1

Attack profile CVSS 3.1 · 8.6

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2020-3533.md and follow it. Check whether this project is affected by CVE-2020-3533. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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