CVE-2021-40112
Cisco Catalyst PON Series Switches Optical Network Terminal Vulnerabilities
- Published
- Updated
- Reserved
- Assigned by
- cisco
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.
Timeline
ID reserved
By cisco
- 2 months later
· 2 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
- EPSS (exploitation in 30 days)
- 1.4% · top 28% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 10.0.
Weakness
Affected products
Cisco · Cisco Catalyst PON Series
- affected n/a
What to do
Exploitation: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.
References (1)
- 20211103 Cisco Catalyst PON Series Switches Optical Network Terminal Vulnerabilities (opens in a new tab)vendor-advisoryx_refsource_CISCOx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-40112)Record last updated .