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CVE Record

CVE-2021-1507: Cisco SD-WAN vManage API Stored Cross-Site Scripting Vulnerability

A vulnerability in an API of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against users of the application web-based interface. This vulnerability exists because the API does not properly validate user-supplied input. An attacker could exploit this vulnerability by sending malicious input to the API. A successful exploit could allow the attacker to execute arbitrary script code in the context of the web-based interface or access sensitive, browser-based information.

MediumCVSS 6.4Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

Cisco SD-WAN vManage had a stored cross-site scripting flaw in an API. An authenticated attacker could submit malicious input that later runs script in the vManage web interface, potentially exposing browser-based sensitive information or altering what users see or do in that session.

Executive priority

Handle in normal patch governance, with higher priority for internet-exposed or shared-admin vManage environments. This is not shown as actively exploited in the supplied sources, but it affects a network management platform where compromise can have outsized operational consequences.

Technical view

CVE-2021-1507 is CWE-79 in Cisco SD-WAN vManage Software. The API failed to properly validate user-supplied input, enabling authenticated remote stored XSS. CVSS 3.1 is 6.4: network reachable, low complexity, low privileges required, no user interaction, changed scope, low confidentiality and integrity impact, no availability impact.

Likely exposure

Exposure is limited to Cisco SD-WAN vManage deployments and requires an authenticated attacker. The source bundle does not provide affected version ranges or CPEs. Publicly reachable or broadly accessible management/API interfaces would raise practical risk.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. Exploitation requires authenticated access and malicious input sent to the affected API, with impact occurring in the web-based interface context.

Researcher notes

Version scoping is incomplete in the supplied bundle. The key condition is improper input validation in a vManage API causing stored XSS. Avoid assuming unauthenticated exploitation, product variants, or fixed versions not stated in the cited sources.

Mitigation direction

  • Check Cisco’s advisory for affected and fixed vManage releases.
  • Apply Cisco-recommended updates or workarounds where applicable.
  • Restrict vManage web and API access to trusted administrative networks.
  • Enforce least privilege for vManage accounts and API users.
  • Review administrative audit logs for suspicious authenticated API activity.

Validation and detection

  • Inventory all Cisco SD-WAN vManage instances.
  • Compare deployed versions with Cisco’s advisory version guidance.
  • Confirm vManage management interfaces are not broadly exposed.
  • Review API-accessible stored fields for unexpected or suspicious content.
  • Check whether compensating access controls are enforced.
Prepared
Confidence
high
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · medium confidence lookup

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.

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cve · low confidence lookup

CVE-2021-1507 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.4 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
6.4CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N3.12.7Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.4Medium
CVSS 3.1 vector shape for CVE-2021-1507Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
CiscoCisco SD-WAN vManagen/aListed
Weakness

CWE details

CWE-79

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-79 · source CWE mapping

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.

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