Security readout for executives and security teams
Plain-English summary
CVE-2020-3337 lets an unauthenticated remote attacker abuse Cisco Umbrella URL handling to redirect a user to an attacker-chosen website. The main business risk is phishing and trust abuse, not system takeover. The source rates it medium severity with user interaction required.
Executive priority
Address through normal vulnerability management unless Cisco guidance or local telemetry shows active abuse. The issue can support phishing but does not, from the supplied evidence, expose data or enable direct compromise.
Technical view
Cisco Umbrella had CWE-601 open redirect behavior in its web server due to improper validation of URL parameters in HTTP requests. The CVSS 3.0 score is 4.7: network reachable, low complexity, no privileges, user interaction required, changed scope, low integrity impact, and no confidentiality or availability impact.
Likely exposure
Exposure is limited to organizations using affected Cisco Umbrella web functionality. The supplied sources do not identify specific affected versions or deployment conditions, so teams should verify exposure directly against Cisco guidance and their Umbrella estate.
Exploitation context
The bundled data does not indicate CISA KEV listing or active exploitation. Exploitation requires a crafted request or link and a user who follows it, making it most relevant to phishing, brand-trust abuse, and security-awareness bypass scenarios.
Researcher notes
The key uncertainty is affected version detail; the bundle lists Cisco Umbrella with versions as n/a. Avoid assuming patch state or exploit activity beyond the Cisco advisory, CVE record, and non-KEV status provided.
Mitigation direction
- Review Cisco’s advisory for affected status and vendor-directed remediation.
- Inventory Cisco Umbrella usage and ownership across the organization.
- Prioritize vendor-recommended updates or configuration changes if Cisco lists them.
- Treat suspicious Umbrella-branded redirects as phishing risk in monitoring and awareness.
- Escalate to Cisco support if version or service impact is unclear.
Validation and detection
- Confirm whether Cisco Umbrella is in use in your environment.
- Check Cisco’s advisory against your service configuration and support status.
- Review phishing telemetry for suspicious redirected links involving Umbrella URLs.
- Use authorized testing to verify redirects cannot leave trusted destinations.
- Document findings, remediation status, and residual user-interaction risk.
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-601: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2020-3337 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
- 4.7 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
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:R/S:C/C:N/I:L/A:N2.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
4.7MediumVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20200617 Cisco Umbrella Open Redirect 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.
URL Redirection to Untrusted Site ('Open Redirect')
URL Redirection to Untrusted Site ('Open Redirect') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.