CVE-2020-3574

highpriority · track · 33EPSS 0.080 · 95 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

8.03% (95th) EPSS

CVSS 7.8 · high

Is it mine?

17 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the TCP packet processing functionality of Cisco IP Phones could allow an unauthenticated, remote attacker to cause the phone to stop responding to incoming calls, drop connected calls, or unexpectedly reload. The vulnerability is due to insufficient TCP ingress packet rate limiting. An attacker could exploit this vulnerability by sending a high and sustained rate of crafted TCP traffic to the targeted device. A successful exploit could allow the attacker to impact operations of the phone or cause the phone to reload, leading to a denial of service (DoS) condition.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco IP Phones with Multiplatform Firmwarecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Webex Room Phonecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.8

v2.07.8highAV:N/AC:L/Au:N/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 10 · impact 6.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 3.9 · impact 3.6

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · Cisco PSIRT US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-371USCWE-371US

affected products (17)

Products and version ranges known to be affected.

Cisco Cisco IP Phones with Multiplatform Firmwareall versionscisco_csafUS
Cisco Cisco Webex Room Phoneall versionscisco_csafUS
Cisco Cisco IP Phones with Multiplatform Firmware≤ n/aenisa_euvdEU
Cisco Systems Inc. Cisco IP Phone 8811 with Multiplatform≤ 11.3.2fstec_bduRU
Cisco Systems Inc. Cisco IP Phone 8841 with Multiplatform≤ 11.3.2fstec_bduRU
Cisco Systems Inc. Cisco IP Phone 8851 with Multiplatform≤ 11.3.2fstec_bduRU
Cisco Systems Inc. Cisco IP Phone 8861 with Multiplatform≤ 11.3.2fstec_bduRU
Cisco Systems Inc. IP DECT 210 Multi-Cell Base Station with Multiplatform≤ 4.8.1fstec_bduRU
Cisco Systems Inc. IP DECT 6825 with Multiplatform≤ 4.8.1fstec_bduRU
cisco ip dect 210 firmware< 4.8.1nvdUScpe:2.3:o:cisco:ip_dect_210_firmware:*:*:*:*:*:*:*:*
cisco ip dect 6825 firmware< 4.8.1nvdUScpe:2.3:o:cisco:ip_dect_6825_firmware:*:*:*:*:*:*:*:*
cisco ip phone 8811 firmware< 11.3.2nvdUScpe:2.3:o:cisco:ip_phone_8811_firmware:*:*:*:*:*:*:*:*
cisco ip phone 8841 firmware< 11.3.2nvdUScpe:2.3:o:cisco:ip_phone_8841_firmware:*:*:*:*:*:*:*:*
cisco ip phone 8851 firmware< 11.3.2nvdUScpe:2.3:o:cisco:ip_phone_8851_firmware:*:*:*:*:*:*:*:*
cisco ip phone 8861 firmware< 11.3.2nvdUScpe:2.3:o:cisco:ip_phone_8861_firmware:*:*:*:*:*:*:*:*
cisco unified ip conference phone 8831 firmware= 9.3(4)nvdUScpe:2.3:o:cisco:unified_ip_conference_phone_8831_firmware:*:*:*:*:*:*:*:*
cisco webex room phone firmware< 1.2.0nvdUScpe:2.3:o:cisco:webex_room_phone_firmware:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-voip-phone-flood-dos-YnU9EXOvCisco IP Phone TCP Packet Flood Denial of Service Vulnerability2020-11-04csaf · cisco_csafUS
A vulnerability in the TCP packet processing functionality of Cisco IP Phones could allow an unauthenticated, remote attacker to cause the phone to stop responding to incoming calls, drop connected calls, or unexpectedly reload. The vulnerability is due to insufficient TCP ingress packet rate limiting. An attacker could exploit this vulnerability by sending a high and sustained rate of crafted TCP traffic to the targeted device. A successful exploit could allow the attacker to impact operations of the phone or cause the phone to reload, leading to a denial of service (DoS) condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf nvd NVD CVE.org MITRE

published 2020-11-06modified 2026-06-17

references (7)

External citations — patches, advisories, analysis.

scry

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