Security readout for executives and security teams
Plain-English summary
Cisco IoT Field Network Director can be knocked into high CPU usage through abusive TLS renegotiation against its web interface. The issue affects availability, not data theft or privilege escalation. Business urgency depends on whether IoT-FND is deployed and whether its web interface is reachable from untrusted networks.
Executive priority
Treat as a moderate availability risk. Prioritize if IoT-FND supports operational field-network management or has a web interface exposed beyond a tightly controlled admin network.
Technical view
The vulnerability is in Cisco IoT-FND web interface handling of TLS renegotiation requests. An unauthenticated remote attacker can send renegotiation requests at high rate, increasing resource use and causing a denial-of-service condition. CVSS 3.0 is 5.3 with network attack vector, low complexity, no privileges, no user interaction, and low availability impact.
Likely exposure
Exposure is limited to organizations running Cisco IoT Field Network Director with the web interface reachable to potential attackers. Internet, partner, or broad internal access raises risk; management-only access reduces practical exposure.
Exploitation context
The provided sources describe a remote unauthenticated DoS condition. The CVE is not listed as KEV in the bundle, and no cited source here confirms active exploitation or public weaponization.
Researcher notes
Evidence supports CWE-399 resource management impact through TLS renegotiation handling. The bundle does not provide exact affected versions, fixed versions, or exploit telemetry, so validation should be anchored to Cisco’s advisory and local exposure review.
Mitigation direction
- Inventory Cisco IoT-FND deployments and identify exposed web interfaces.
- Review Cisco’s advisory for affected release and fixed software guidance.
- Restrict IoT-FND web access to trusted management networks where feasible.
- Monitor affected systems for sustained CPU spikes and availability degradation.
- Prioritize remediation for internet-facing or broadly reachable management interfaces.
Validation and detection
- Confirm Cisco IoT-FND presence and version against Cisco’s advisory.
- Check whether the web interface is reachable from untrusted networks.
- Review monitoring for abnormal CPU usage or TLS negotiation patterns.
- Verify remediation status using vendor guidance and change records.
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-399: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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 lookupCVE-2019-1957 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
- Medium
- CVSS
- 5.3 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
5.3MediumVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Source materials
- CVE List V5 sourceCVE List V5
- 20190807 Cisco IoT Field Network Director TLS Renegotiation Denial of Service VulnerabilityCVE 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.
Resource Management Errors
Resource Management Errors represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.