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CVE Record

CVE-2021-34731: Cisco Prime Access Registrar Stored Cross-Site Scripting Vulnerability

A vulnerability in the web-based management interface of Cisco Prime Access Registrar could allow an authenticated, remote attacker to perform a stored cross-site scripting attack on an affected system. This vulnerability exists because the web-based management interface does not sufficiently validate user-supplied input. An attacker could exploit this vulnerability by injecting malicious code into specific pages of the interface. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information. To exploit this vulnerability, the attacker would need valid administrative credentials. Cisco expects to release software updates that address this vulnerability.

MediumCVSS 4.8Not KEV-listedUpdated
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

Cisco Prime Access Registrar’s web management interface can store unsafe input. An attacker who already has valid administrative credentials could place script content that later runs in another user’s browser inside the affected interface, potentially exposing browser-based information or altering interface interactions.

Executive priority

Treat this as a moderate-priority remediation item. It is not described as actively exploited and requires admin credentials, but the affected interface is privileged and could expose sensitive browser-based information if abused.

Technical view

CVE-2021-34731 is a stored cross-site scripting issue caused by insufficient validation of user-supplied input in Cisco Prime Access Registrar’s web-based management interface. CVSS 3.1 is 4.8: network-reachable, low complexity, high privileges required, user interaction required, changed scope, low confidentiality and integrity impact, no availability impact.

Likely exposure

Exposure is limited to organizations running Cisco Prime Access Registrar where the web management interface is reachable by administrative users. The source bundle does not identify affected versions or CPEs, so asset owners must confirm product presence and vendor applicability.

Exploitation context

The sources do not report known active exploitation, and the CVE is not listed as KEV in the bundle. Exploitation requires valid administrative credentials and user interaction, which lowers broad internet-scale risk but keeps insider, compromised-admin, and shared-admin-console scenarios relevant.

Researcher notes

The public bundle provides the vulnerability class, attack prerequisites, affected product, CVSS vector, and Cisco advisory reference, but not affected version ranges or final fixed releases. Avoid broad claims about exploit availability or product scope without additional vendor evidence.

Mitigation direction

  • Check Cisco’s advisory for current fixed-release guidance.
  • Apply Cisco-provided software updates when available and applicable.
  • Limit management interface access to trusted administrative networks.
  • Review and tighten administrative account access.
  • Monitor Cisco guidance because affected versions are not listed in the bundle.

Validation and detection

  • Inventory Cisco Prime Access Registrar deployments.
  • Confirm whether the web management interface is enabled and reachable.
  • Check Cisco advisory applicability against installed versions.
  • Review administrative account lists for unnecessary access.
  • Look for unusual administrative interface changes or stored content.
Prepared
Confidence
medium
Sources
3

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.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-34731 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
4.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/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
4.8CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N1.72.7Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

4.8Medium
CVSS 3.1 vector shape for CVE-2021-34731Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/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 Prime Access Registrarn/aListed
Weakness

CWE details

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.