Security readout for executives and security teams
Plain-English summary
CVE-2020-3400 lets a logged-in user on Cisco IOS XE Web UI reach functions they should not have. In the stated impact, a read-only user could perform admin-level actions. That makes it a high business risk where device management interfaces are exposed to many users.
Executive priority
Prioritize remediation for internet-reachable or broadly accessible management interfaces. The main concern is privilege escalation inside network infrastructure management, which can affect confidentiality, configuration integrity, and availability.
Technical view
Cisco describes this as insufficient authorization in the IOS XE Web UI, mapped to CWE-862. The CVSS 3.0 score is 8.8, requiring network access and low privileges, with high confidentiality, integrity, and availability impact. A crafted HTTP request is the stated trigger, but no exploit details are provided here.
Likely exposure
Exposure is most likely on Cisco IOS XE devices with the Web UI feature enabled and reachable by authenticated users. The bundle does not provide affected version ranges or fixed releases, so teams must verify device versions against Cisco guidance.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Cisco states an authenticated remote attacker could exploit it by sending a crafted HTTP request to the Web UI, potentially gaining access to unauthorized admin functions.
Researcher notes
The bundle identifies Cisco IOS XE Web UI authorization bypass with CVSS 8.8 and CWE-862, but lacks affected version ranges, fixed versions, and independent exploitation evidence. Treat version validation and vendor advisory review as mandatory before making exposure claims.
Mitigation direction
- Review the Cisco advisory for affected and fixed IOS XE release guidance.
- Inventory IOS XE devices with the Web UI feature enabled.
- Apply Cisco-recommended software updates or mitigations after confirming applicability.
- Restrict Web UI access to trusted management networks where feasible.
- Review low-privilege accounts with access to device management interfaces.
Validation and detection
- Confirm whether each IOS XE device has Web UI enabled.
- Compare running IOS XE versions against Cisco advisory guidance.
- Verify management interfaces are not broadly reachable.
- Review admin and read-only account assignments on affected devices.
- Check logs for unusual Web UI activity by low-privilege accounts.
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-862: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-3400 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
- 8.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200924 Cisco IOS XE Software Web UI Authorization Bypass 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.
Missing Authorization
Missing Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.