How severe is CVE-2020-3409?

CVE-2020-3409 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-3409 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3409?

CVE-2020-3409 primarily affects Cisco Ios. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-3409?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-3409 published?

CVE-2020-3409 was published on 2020-09-24 and last updated on 2026-06-17.

CVE-2020-3409

CVE-2020-3409 is a high-severity vulnerability in Cisco Ios with a CVSS 3.x base score of 7.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: High (CVSS 3.x base score 7.4)
CVSS v2: 6.1
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Cisco Ios
Published: 2020-09-24
Last modified: 2026-06-17

Description

A vulnerability in the PROFINET feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause an affected device to crash and reload, resulting in a denial of service (DoS) condition on the device. The vulnerability is due to insufficient processing logic for crafted PROFINET packets that are sent to an affected device. An attacker could exploit this vulnerability by sending crafted PROFINET packets to an affected device for processing. A successful exploit could allow the attacker to cause the device to crash and reload, resulting in a DoS condition on the device.

Frequently asked questions

What is CVE-2020-3409?: A vulnerability in the PROFINET feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause an affected device to crash and reload, resulting in a denial of service (DoS) condition on the device. The vulnerability is due to insufficient processing logic for crafted PROFINET packets that are sent to an affected device. An attacker could exploit this vulnerability by sending crafted PROFINET packets to an affected device for processing. A successful exploit could allow the attacker to cause the device to crash and reload, resulting in a DoS condition on the device.
How severe is CVE-2020-3409?: CVE-2020-3409 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-3409 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3409?: CVE-2020-3409 primarily affects Cisco Ios. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3409?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-3409 published?: CVE-2020-3409 was published on 2020-09-24 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-profinet-J9QMCHPB

Affected products (4)

cpe:2.3:o:cisco:ios:15.2\(7\)e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:15.2\(7\)e:*:*:*:*:*:*:*
cpe:2.3:a:cisco:ios_xe:16.11.1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:16.11.1a:*:*:*:*:*:*:*

More vulnerabilities in Cisco Ios

CVE-2011-3271 — Critical (CVSS 10.0): Unspecified vulnerability in the Smart Install functionality in Cisco IOS 12.2 and 15.1 allows remote attackers to…
CVE-2011-0935 — Critical (CVSS 10.0): The PKI functionality in Cisco IOS 15.0 and 15.1 does not prevent permanent caching of certain public keys, which…
CVE-2010-1574 — Critical (CVSS 10.0): IOS 12.2(52)SE and 12.2(52)SE1 on Cisco Industrial Ethernet (IE) 3000 series switches has (1) a community name of…
CVE-2010-0581 — Critical (CVSS 10.0): Unspecified vulnerability in the SIP implementation in Cisco IOS 12.3 and 12.4 allows remote attackers to execute…
CVE-2010-0580 — Critical (CVSS 10.0): Unspecified vulnerability in the SIP implementation in Cisco IOS 12.3 and 12.4 allows remote attackers to execute…
CVE-2006-4950 — Critical (CVSS 10.0): Cisco IOS 12.2 through 12.4 before 20060920, as used by Cisco IAD2430, IAD2431, and IAD2432 Integrated Access Devices,…

All CVEs affecting Cisco Ios →

Other CWE-400 (Uncontrolled Resource Consumption) vulnerabilities

CVE-2026-46775 — Critical (CVSS 9.9): Vulnerability in Oracle REST Data Services (component: Core). Supported versions that are affected are 24.2.0-26.1.0.…
CVE-2025-61303 — Critical (CVSS 9.8): Hatching Triage Sandbox Windows 10 build 2004 (2025-08-14) and Windows 10 LTSC 2021(2025-08-14) contains a…
CVE-2025-43193 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.6, macOS Sonoma 14.7.7,…
CVE-2025-24269 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.4. An app may be able to…
CVE-2025-24264 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in Safari 18.4, iOS 18.4 and iPadOS 18.4,…
CVE-2025-24260 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.4, macOS Sonoma 14.7.5,…

Browse all CWE-400 (Uncontrolled Resource Consumption) vulnerabilities →