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CVE Record

CVE-2021-1607: Cisco Identity Services Engine Stored Cross-Site Scripting Vulnerabilities

Multiple vulnerabilities in the web-based management interface of Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against a user. These vulnerabilities exist because the web-based management interface does not sufficiently validate user-supplied input. An attacker could exploit these vulnerabilities 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 these vulnerabilities, the attacker would need valid administrative credentials.

MediumCVSS 4.8Not KEV-listedUpdated
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a stored cross-site scripting issue in Cisco Identity Services Engine’s web management interface. A malicious authenticated administrator could store script content that runs when another user views affected pages, potentially exposing browser-based information or changing interface actions.

Executive priority

Handle through normal vulnerability management unless ISE admin credentials are suspected compromised or management access is broadly exposed. Prioritize confirming version exposure, limiting admin access, and applying Cisco guidance before the next maintenance window.

Technical view

CVE-2021-1607 covers multiple CWE-79 flaws in Cisco ISE Software caused by insufficient validation of user-supplied input in management UI pages. 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 primarily organizations running Cisco Identity Services Engine Software with users who can access the web-based management interface. Risk depends on deployed versions and admin access controls; the supplied bundle does not identify specific affected or fixed versions.

Exploitation context

The source states exploitation requires valid administrative credentials and a victim user interaction. There is no KEV listing and no provided source claims active exploitation. This is more relevant to insider, compromised-admin, or lateral-movement scenarios than initial compromise.

Researcher notes

Evidence supports stored XSS in Cisco ISE’s management UI with high privileges and user interaction required. The bundle lacks affected-version and fixed-release detail, so remediation should be anchored to Cisco’s advisory rather than inferred.

Mitigation direction

  • Review the Cisco advisory for affected and fixed ISE releases.
  • Apply Cisco-recommended updates or mitigations once version applicability is confirmed.
  • Limit ISE management interface access to trusted administrative networks.
  • Audit and minimize accounts with ISE administrative privileges.
  • Monitor administrative activity for suspicious content changes or unexpected UI behavior.

Validation and detection

  • Inventory Cisco ISE deployments and record exact software versions.
  • Compare deployed versions against Cisco’s advisory guidance.
  • Confirm management UI access is restricted to authorized administrators.
  • Review admin account lists for stale, shared, or excessive privileges.
  • Check logs for unusual administrative changes around interface 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-2021-1607 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-2021-1607Attack 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 Identity Services Engine Softwaren/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.