Which products and versions are affected by CVE-2020-3161?

Affected: 8831 Firmware (Cisco) versions 10.3\(1\)es14, 11.0\(1\), 11.0\(5\)sr1; Ip Phone 7811 Firmware (Cisco) versions 11.0\(1\); Ip Phone 7821 Firmware (Cisco) versions 11.0\(1\), among others. The full list is in the CVE brief.

Is CVE-2020-3161 being exploited in the wild?

It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Nov 3, 2021.

Is CVE-2020-3161 in the CISA KEV catalog?

Yes. It was added on Nov 3, 2021 with a federal remediation due date of May 3, 2022.

Is there a public exploit for CVE-2020-3161?

Public exploit code is available.

Is there a fix for CVE-2020-3161?

No fixed version is listed yet; check the vendor advisory for mitigations.

How urgently should CVE-2020-3161 be patched?

Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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Vulnerability Intelligence

CVE-2020-3161

CriticalExploitedPublic exploit

Published Apr 15, 2020 · Updated Oct 28, 2025

Key Facts

Patch immediately

CVE-2020-3161 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting 8831 Firmware (Cisco), Ip Phone 7811 Firmware (Cisco), Ip Phone 7821 Firmware (Cisco) and 11 more products.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Nov 3, 2021. Public exploit code is available.
EPSS estimates a 84% probability of exploitation in the next 30 days.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

9.8

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

EPSS (30-day exploit likelihood)

84%

Higher than 99.6% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2020-3161 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

A vulnerability in the web server for Cisco IP Phones could allow an unauthenticated, remote attacker to execute code with root privileges or cause a reload of an affected IP phone, resulting in a denial of service (DoS) condition. The vulnerability is due to a lack of proper input validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web server of a targeted device. A successful exploit could allow the attacker to remotely execute code with root privileges or cause a reload of an affected IP phone, resulting in a DoS condition.

Known-Exploited Catalog Listings

Catalog	Added	Remediation due	Ransomware use
CISA KEV	Nov 3, 2021	May 3, 2022	Not reported
Industry KEV feed	Nov 3, 2021	May 3, 2022	Not reported
CIRCL KEV	Nov 3, 2021	May 3, 2022	Not reported
ENISA EUVD	Nov 3, 2021	n/a	Not reported

Required action: Apply updates per vendor instructions.

Affected Products

32 affected entries in total

Product	Affected versions	Fixed in
8831 FirmwareCisco	10.3\(1\)es14, 11.0\(1\), 11.0\(5\)sr1	n/a
Ip Phone 7811 FirmwareCisco	11.0\(1\)	n/a
Ip Phone 7821 FirmwareCisco	11.0\(1\)	n/a
Ip Phone 7841 FirmwareCisco	11.0\(1\)	n/a
Ip Phone 7861 FirmwareCisco	11.0\(1\)	n/a

9 more affected products in the full CVE brief

Timeline

Publicly disclosed
Apr 15, 2020
Added to CISA KEV
Nov 3, 2021
Added to Industry KEV feed
Nov 3, 2021
Added to CIRCL KEV
Nov 3, 2021
Added to ENISA EUVD
Nov 3, 2021
Last updated
Oct 28, 2025

Weakness Type

CWE-20 Improper Input Validation

References

FAQ

Common Questions.

A vulnerability in the web server for Cisco IP Phones could allow an unauthenticated, remote attacker to execute code with root privileges or cause a reload of an affected IP phone, resulting in a denial of service (DoS) condition.
Affected: 8831 Firmware (Cisco) versions 10.3\(1\)es14, 11.0\(1\), 11.0\(5\)sr1; Ip Phone 7811 Firmware (Cisco) versions 11.0\(1\); Ip Phone 7821 Firmware (Cisco) versions 11.0\(1\), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Nov 3, 2021.
Yes. It was added on Nov 3, 2021 with a federal remediation due date of May 3, 2022.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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