Security readout for executives and security teams
Plain-English summary
CVE-2020-27128 lets an authenticated remote user make Cisco SD-WAN vManage write files where it should not. The main business risk is unauthorized modification of a management platform. The source bundle does not identify active exploitation or exact affected/fixed releases.
Executive priority
Treat this as a moderate-priority management-plane issue. It is not confirmed exploited in the supplied sources, but unauthorized file writes on SD-WAN management infrastructure can undermine trust in network operations and should be remediated during the next security maintenance window.
Technical view
Cisco describes improper request validation in vManage application data endpoints. A low-privileged authenticated attacker could send malicious API requests that enable directory traversal and arbitrary file creation on the target system. CVSS 3.1 is 6.5, with high integrity impact and no confidentiality or availability impact stated.
Likely exposure
Exposure is limited to Cisco SD-WAN vManage Software deployments where an attacker can authenticate and reach the affected application APIs. The provided bundle does not specify vulnerable version ranges, so inventory must be compared against Cisco’s advisory.
Exploitation context
The CVE is not listed as KEV in the provided bundle, and no cited source confirms active exploitation. Exploitation requires network access to vManage APIs and valid credentials, but the attack complexity is rated low once those conditions are met.
Researcher notes
Mapped weakness is CWE-22. CVSS vector shows network attack, low complexity, low privileges required, no user interaction, unchanged scope, and high integrity impact. The supplied evidence is incomplete on version ranges, exploit activity, and fixes; Cisco’s advisory is the authoritative source for those details.
Mitigation direction
- Review the Cisco advisory for affected and fixed vManage releases.
- Restrict vManage management/API access to trusted administrative networks.
- Audit vManage accounts and remove unnecessary authenticated access.
- Monitor for unexpected file creation or integrity changes on vManage systems.
- Apply Cisco-provided updates or workarounds if the advisory lists them.
Validation and detection
- Inventory all Cisco SD-WAN vManage instances and their software versions.
- Confirm whether exposed instances match Cisco advisory affected releases.
- Review vManage authentication logs for unusual low-privilege API activity.
- Check file integrity monitoring for unexpected writes on vManage systems.
- Verify compensating controls restrict access to vManage management endpoints.
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-22: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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 lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-27128 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
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/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:L/UI:N/S:U/C:N/I:H/A:N2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20201104 Cisco SD-WAN vManage Software Arbitrary File Creation 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 Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.