CVE-2021-40112

Name: CVE-2021-40112
Creator: NVD / NIST
Published: 2021-11-04T16:15:09.14+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.39%

Last modified Jun 17, 2026

CVE-2021-40112 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Multiple vulnerabilities in the web-based management interface of the Cisco Catalyst Passive Optical Network (PON) Series Switches Optical Network Terminal (ONT) could allow an unauthenticated, remote attacker to perform the following actions: Log in with a default credential if the Telnet protocol is enabled Perform command injection Modify the configuration For more information about these vulnerabilities, see the Details section of this advisory.. EPSS estimates a 1.39% chance of exploitation in the next 30 days.

Description

Multiple vulnerabilities in the web-based management interface of the Cisco Catalyst Passive Optical Network (PON) Series Switches Optical Network Terminal (ONT) could allow an unauthenticated, remote attacker to perform the following actions: Log in with a default credential if the Telnet protocol is enabled Perform command injection Modify the configuration For more information about these vulnerabilities, see the Details section of this advisory.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.39%

68.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-284

Affected Software

Vendor	Product	Versions
Cisco	Catalyst Pon Switch Cgp-Ont-1p Firmware	< 1.1.1.14
Cisco	Catalyst Pon Switch Cgp-Ont-4p Firmware	< 1.1.3.17
Cisco	Catalyst Pon Switch Cgp-Ont-4pvc Firmware	< 1.1.3.17
Cisco	Catalyst Pon Switch Cgp-Ont-4tvcw Firmware	< 1.1.3.17
Cisco	Catalyst Pon Switch Cgp-Ont-4pv Firmware	< 1.1.3.17

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-catpon-multivulns-CE3DSYGrPatch, Vendor Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-catpon-multivulns-CE3DSYGrPatch, Vendor Advisory

Timeline

Published: Nov 4, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-40112?

How severe is CVE-2021-40112?

CVE-2021-40112 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.39% probability of exploitation in the next 30 days.

How do I fix CVE-2021-40112?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-40112?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST