Security readout for executives and security teams
Plain-English summary
CVE-2020-3599 is a reflected XSS flaw in Cisco ASA Software’s web-based management interface. An attacker cannot exploit it alone; they must persuade a management-interface user to click a crafted link. Success could run script in that interface context or access sensitive browser-based information.
Executive priority
Treat this as a moderate-priority management-plane issue. It is not described as wormable or actively exploited in the supplied sources, but ASA devices are security infrastructure, so confirm exposure and vendor remediation status promptly.
Technical view
The Cisco ASA web-based management interface did not properly validate user-supplied input, enabling reflected cross-site scripting. The vulnerability is unauthenticated and network-reachable, but requires user interaction. CVSS v3.1 is 6.1: AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. CWE-79 applies.
Likely exposure
Exposure is most likely in organizations running Cisco Adaptive Security Appliance Software with the web-based management interface used by administrators. The source bundle does not identify specific affected versions, CPEs, fixed releases, or deployment conditions.
Exploitation context
The source describes a crafted-link scenario requiring social engineering of a user of the interface. The CVE is not listed as KEV in the supplied bundle, and no cited source here confirms active exploitation.
Researcher notes
Evidence is limited to the CVE record and Cisco advisory reference. The bundle provides impact, attack conditions, CVSS, CWE, and affected product family, but not version ranges, fixed versions, workarounds, or proof of exploitation.
Mitigation direction
- Review Cisco’s advisory for affected releases, fixed software, and official workarounds.
- Apply Cisco-provided updates or mitigations when confirmed applicable to your ASA version.
- Restrict web management access to trusted administrative networks where operationally possible.
- Warn ASA administrators against opening unsolicited links while authenticated to management interfaces.
Validation and detection
- Inventory Cisco ASA Software deployments and identify enabled web-based management interfaces.
- Check each ASA version against the Cisco advisory and internal asset records.
- Confirm whether administrators can reach the interface from untrusted networks.
- Review browser and management-interface logs for suspicious crafted-link access patterns.
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-79: 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-2020-3599 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
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/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:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N2.82.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20201021 Cisco Adaptive Security Appliance Software Web-Based Management Interface Reflected Cross-Site Scripting 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 Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.