CVE-2021-40113
A public proof of concept exists; no exploitation attested.
- Published2021-11-04
- Fixed in1.1.1.14
- WeaknessCWE-284 · CWE-78
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
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
dates in UTC- 2021-11-0416:15CVE publishedNVD
- 2026-10-2319:23First public proof of conceptPoC-in-GitHub
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-40113?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-40113?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 1.1 | < 1.1.1.14 | 1.1.1.14 | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 1.1 | < 1.1.3.17 | 1.1.3.17 | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 1.1 | < 1.1.3.17 | 1.1.3.17 | NVD |
2 more products in the sources.
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update Cisco catalyst pon switch cgp-ont-1p firmware to 1.1.1.14
Advisories and patches
- tools.cisco.comPatch · Vendor Advisory
Detection
read 2026-10-23 19:23 UTC- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
Sources
- CISA-ADPSSVC decisionnone2024-11-07
- OpenCVESSVC decisionnone—
- CNACVSS 3.110read 2026-10-23
- NVDCVSS 3.19.8read 2026-10-23
- NVDCVSS 2.07.5read 2026-10-23
- CNAweakness (CWE)CWE-284read 2026-10-23
- NVDweakness (CWE)CWE-78read 2026-10-23
- FIRST EPSSEPSS score4.6 %2026-10-22
- PoC-in-GitHubproof of concept1read 2026-10-23
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- 2021-11-04
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-40113?
Is CVE-2021-40113 actively exploited?
What is the CVSS score for CVE-2021-40113?
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