Security readout for executives and security teams
Plain-English summary
CVE-2019-1947 can let an unauthenticated remote attacker make a Cisco Email Security Appliance consume all CPU, stopping email filtering service. The business impact is availability: mail security and mail flow may be disrupted, and recovery may require manual intervention.
Executive priority
Treat this as a high-priority availability risk for email security infrastructure. It does not indicate data theft or message tampering, but it can interrupt mail filtering and may require hands-on recovery if successfully triggered.
Technical view
Cisco AsyncOS for Cisco ESA has improper handling in email message filtering when processing email messages with large attachments. The CVSS 3.0 score is 8.6, with network attack vector, low complexity, no privileges, no user interaction, and high availability impact.
Likely exposure
Organizations using Cisco Email Security Appliance for inbound or outbound mail filtering are the likely exposure group. The source bundle does not list specific affected AsyncOS versions, so teams must confirm applicability through Cisco’s advisory and their deployed ESA versions.
Exploitation context
The source states exploitation is remote and unauthenticated through email traffic processed by the targeted device. The bundle does not cite CISA KEV listing or any public evidence of active exploitation, so active exploitation should not be assumed.
Researcher notes
This is a CWE-20 input handling issue in ESA message filtering. The provided data does not include affected version ranges, patched versions, or independent exploit reporting. Focus validation on product presence, AsyncOS applicability, availability monitoring, and Cisco advisory alignment.
Mitigation direction
- Review Cisco’s advisory for affected releases and fixed software guidance.
- Inventory all Cisco ESA appliances and record AsyncOS versions.
- Prioritize remediation for internet-facing or high-volume mail filtering deployments.
- Prepare operational recovery procedures for high-CPU ESA denial-of-service events.
- Check Cisco guidance before applying compensating controls.
Validation and detection
- Confirm whether Cisco ESA is deployed in the mail path.
- Compare deployed AsyncOS versions against Cisco’s advisory.
- Review monitoring for sustained ESA CPU saturation or mail-flow disruption.
- Verify remediation status after applying Cisco-recommended updates or mitigations.
- Document whether manual recovery procedures are tested.
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
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CWE-20: Exact CWE lookup
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Open ATT&CK lookupCVE-2019-1947 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 8.6 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/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:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.6HighVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200219 Cisco Email Security Appliance 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.