Security readout for executives and security teams
Plain-English summary
This is a critical Cisco Catalyst PON ONT issue affecting the web management interface. A remote unauthenticated attacker could potentially gain access, inject commands, or change device configuration. For business leaders, the risk is highest where these ONT management interfaces are reachable from untrusted networks.
Executive priority
Treat as urgent for environments using Cisco Catalyst PON ONT devices. Prioritize containment of management-plane exposure, vendor guidance review, and remediation planning before routine maintenance windows if devices are reachable remotely.
Technical view
CVE-2021-40113 covers multiple web-based management interface vulnerabilities in Cisco Catalyst PON Series Switches Optical Network Terminals. The CVSS 3.1 score is 10.0 with network attack vector, no privileges, no user interaction, scope change, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely limited to organizations using Cisco Catalyst PON Series ONT devices, especially where web management or Telnet-enabled management paths are reachable remotely. The bundle does not identify specific versions or CPEs.
Exploitation context
The supplied sources do not show CISA KEV listing or confirm active exploitation. The described impact is severe because exploitation may be unauthenticated and remote, but exploit availability is not established in the provided evidence.
Researcher notes
The bundle names CWE-284 and describes multiple management-interface weaknesses, but does not include per-bug identifiers, affected version ranges, fixed versions, or exploit evidence. Avoid broad product assumptions beyond Cisco Catalyst PON Series ONT devices.
Mitigation direction
- Review Cisco advisory for affected models, fixed releases, and documented workarounds.
- Inventory Cisco Catalyst PON Series ONT deployments and ownership.
- Restrict web management access to trusted administrative networks only.
- Disable Telnet where Cisco guidance and operations allow.
- Remove default credentials and rotate administrative credentials after remediation.
Validation and detection
- Confirm whether Cisco Catalyst PON Series ONT devices are deployed.
- Check whether web management is reachable from untrusted networks.
- Verify Telnet status on affected ONT management paths.
- Compare device software and configuration against Cisco advisory guidance.
- Review logs for unexpected configuration changes or administrative access.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-40113 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 10 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H3.96Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
10CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20211103 Cisco Catalyst PON Series Switches Optical Network Terminal VulnerabilitiesCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.