Security readout for executives and security teams
An authenticated remote user could disrupt Cisco Expressway Series or Cisco TelePresence VCS by sending malformed XML through SIP-related phone book handling. Successful exploitation can drive CPU to 100%, causing service denial and possibly requiring manual recovery. Exposure is most likely where Cisco Expressway Series or Cisco TelePresence VCS is deployed below release X12.5.1. The bundle does not provide a complete vulnerable version matrix, so teams should verify product and release status against Cisco guidance. Treat as a high-priority availability risk for video communications infrastructure, especially where systems are exposed to many authenticated users. It is not described as data theft or privilege escalation. Mitigation focus: Upgrade affected systems to Cisco Expressway/VCS X12.5.1 or later.; Review Cisco’s advisory for product-specific fixed-release guidance.; Prioritize internet-facing or broadly reachable SIP deployments..
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
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ATT&CK lookup starting points
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CWE-20: Exact CWE lookup
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Open ATT&CK lookupCVE-2019-1721 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
- High
- CVSS
- 7.7 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/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:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H3.14Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.7HighVector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20190417 Cisco Expressway Series and Cisco TelePresence Video Communication Server 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.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.