Security readout for executives and security teams
Plain-English summary
Cisco SD-WAN vManage systems running in cluster mode may expose sensitive system information through a cluster management interface that lacks authentication. An attacker on the network path to that interface would not need credentials. The known impact is confidentiality only, not system takeover or service disruption.
Executive priority
Treat this as a targeted remediation item for SD-WAN management infrastructure. It is not rated critical, but unauthenticated exposure of management information can aid follow-on attacks and should be addressed promptly where cluster-mode vManage is deployed.
Technical view
CVE-2021-1535 is a CWE-497 information disclosure issue in Cisco SD-WAN vManage Software. Cisco describes unauthenticated remote access to sensitive information via a crafted request to the cluster management interface. The CVSS 3.1 score is 5.3, with network attack vector, low complexity, no privileges, no user interaction, and low confidentiality impact.
Likely exposure
Exposure is limited to Cisco SD-WAN vManage deployments operating in cluster mode. Standalone deployments are not described as affected in the provided sources. Internet or broadly reachable cluster management interfaces increase concern.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The vulnerability is remotely reachable and unauthenticated, but impact is limited to information disclosure based on the provided CVSS vector.
Researcher notes
The provided evidence does not include exact affected or fixed version ranges. Validation should focus on cluster-mode vManage presence, interface exposure, and Cisco advisory mapping. Avoid assuming exploit availability or broader Cisco SD-WAN component impact from this record alone.
Mitigation direction
- Inventory Cisco SD-WAN vManage deployments and identify cluster-mode systems.
- Review Cisco’s advisory for affected releases and fixed software guidance.
- Restrict cluster management interface access to trusted management networks.
- Monitor access to the cluster management interface for unexpected remote requests.
Validation and detection
- Confirm whether each Cisco SD-WAN vManage instance runs in cluster mode.
- Compare installed versions with Cisco’s advisory and current vendor guidance.
- Validate that the cluster management interface is not broadly reachable.
- Review logs for unusual unauthenticated access attempts to 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-497: 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-2021-1535 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 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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:N/S:U/C:L/I:N/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210505 Cisco SD-WAN vManage Information Disclosure 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.
Exposure of Sensitive System Information to an Unauthorized Control Sphere
Exposure of Sensitive System Information to an Unauthorized Control Sphere represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.