Security readout for executives and security teams
Plain-English summary
This flaw lets an unauthenticated remote attacker slow affected Cisco security appliances by forcing high CPU use in the web management GUI. The appliance should remain operational, but management responsiveness and overall performance may degrade, which can disrupt security operations during an attack or incident.
Executive priority
Treat this as a moderate operational resilience issue. It is not described as data theft or full device compromise, but it can degrade security appliance performance. Escalate priority if management interfaces are reachable from the internet or critical monitoring depends on these appliances.
Technical view
CVE-2020-3164 affects Cisco AsyncOS web-based management interfaces for ESA, WSA, and SMA. Improper validation of specific HTTP request headers allows malformed HTTP requests to trigger prolonged high CPU utilization in GUI processes. CVSS 3.0 is 5.3 with network attack vector, low complexity, no privileges, and low availability impact.
Likely exposure
Exposure is most relevant where Cisco ESA, WSA, or SMA management GUIs are reachable from untrusted networks. The source bundle does not specify affected AsyncOS versions or configurations beyond the product families and web-based management interface.
Exploitation context
The source bundle reports unauthenticated remote exploitability for denial of service. It does not show CISA KEV listing, active exploitation, public exploit availability, or confirmed in-the-wild campaigns.
Researcher notes
The evidence supports CWE-20 improper input validation in HTTP header handling for Cisco AsyncOS GUI services. Affected version and fix details are not included in the provided bundle, so validation should be tied to Cisco’s advisory rather than inferred product version ranges.
Mitigation direction
- Review the Cisco advisory for fixed AsyncOS releases and official workarounds.
- Inventory Cisco ESA, WSA, and SMA appliances in your environment.
- Restrict management GUI access to trusted administrative networks where possible.
- Monitor affected appliances for sustained GUI process CPU spikes.
- Prioritize remediation for internet-reachable management interfaces.
Validation and detection
- Confirm whether ESA, WSA, or SMA appliances are deployed.
- Identify AsyncOS versions and compare them with Cisco advisory guidance.
- Check whether the web management GUI is exposed beyond trusted administrators.
- Review device CPU and GUI responsiveness trends for DoS symptoms.
- Check logs for malformed HTTP requests targeting management interfaces.
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-20: 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-2020-3164 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
- 20200304 Cisco ESA, Cisco WSA, and Cisco SMA GUI 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.