Cisco IP Phone TCP Packet Flood Denial of Service Vulnerability
Published Nov 6, 2020
7.5
HIGHCVSS 3.1
EPSS 8.03%
Description
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.
Affected products
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||
|---|---|---|---|---|---|---|
| Cisco | Cisco IP Phones with Multiplatform Firmware | n/a |
|
Configuration 1
- < 4.8.1
Running on/with
- n/a
Configuration 2
- < 4.8.1
Running on/with
- n/a
Configuration 3
- < 11.3.2
Running on/with
- n/a
Configuration 4
- < 11.3.2
Running on/with
- n/a
Configuration 5
- < 11.3.2
Running on/with
- n/a
Configuration 6
- < 11.3.2
Running on/with
- n/a
Configuration 7
- 9.3\(4\)
Running on/with
- n/a
Configuration 8
- < 1.2.0
Running on/with
- n/a
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
No CVSS v3.0 score for this CVE.
AV:N/AC:L/Au:N/C:N/I:N/A:C
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Nov 13, 2024 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 4, 2026.
Score over time
2021-2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (15 key points)
Flat stretches are collapsed. Showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 4, 2026 | 8.03% (0.08030) | 94.62th | v5 (v2026.06.15) |
| Jun 15, 2026 | 7.94% (0.07935) | 93.97th | v5 (v2026.06.15) |
| Jan 3, 2026 | 3.18% (0.03181) | 86.63th | v4 (v2025.03.14) |
| Nov 24, 2025 | 1.70% (0.01703) | 81.72th | v4 (v2025.03.14) |
| Jul 20, 2024 | 0.16% (0.00159) | 52.88th | v3 (v2023.03.01) |
| Jul 23, 2023 | 0.16% (0.00159) | 51.65th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.14% (0.00137) | 47.42th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.05% (0.01055) | 52.13th | v2 (v2022.01.01) |
| Sep 17, 2022 | 1.05% (0.01055) | 50.47th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.05% (0.01055) | 48.43th | v2 (v2022.01.01) |
| Feb 4, 2022 | 4.50% (0.04499) | 74.08th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.86% (0.02857) | 63.60th | v1 |
| Jan 6, 2022 | 2.86% (0.02857) | 63.25th | v1 |
| Sep 1, 2021 | 0.65% (0.00651) | 45.91th | v1 |
| Apr 14, 2021 | 0.65% (0.00651) | 0.00th | v1 |
References (1)
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phone-flood-dos-YnU9EXOv vendor-advisoryx_refsource_CISCOPatchVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phone-flood-dos-YnU9EXOv | vendor-advisoryx_refsource_CISCOPatchVendor Advisory |
Change history (0)
No recorded changes yet.