Security readout for executives and security teams
Plain-English summary
This is a medium-severity XSS in Cisco ISE's management interface. An attacker already holding administrative credentials could place malicious script on specific interface pages, affecting another user who views them. Business risk is mainly privileged-access abuse and browser-session data exposure, not unauthenticated takeover.
Executive priority
Handle through normal vulnerability management with elevated attention for privileged-access environments. It is not shown as actively exploited, but Cisco ISE is security-critical infrastructure, and compromised administrator access can amplify business impact.
Technical view
CVE-2021-34759 is CWE-79 improper input validation in Cisco Identity Services Engine Software's web-based management interface. CVSS 3.1 is 4.8: network reachable, low complexity, high privileges required, user interaction required, changed scope, limited confidentiality and integrity impact, and no availability impact.
Likely exposure
Organizations running Cisco Identity Services Engine Software may be exposed if affected management interfaces are reachable by administrative users. The source bundle does not provide affected version ranges or fixed release details, so inventory confirmation against Cisco guidance is required.
Exploitation context
The provided sources and KEV flag do not show active exploitation. Exploitation requires valid administrative credentials and a separate user interaction with affected interface pages. The main realistic scenarios are malicious administrators, compromised admin accounts, or post-compromise lateral abuse.
Researcher notes
Evidence is strong for vulnerability type, affected product, prerequisites, and CVSS. The provided bundle lacks affected version ranges, fixed releases, and detailed page locations. Avoid assuming exploit availability or specific remediation beyond Cisco's advisory.
Mitigation direction
- Review Cisco's advisory for affected and fixed ISE releases.
- Apply Cisco-recommended updates or workarounds where applicable.
- Restrict ISE management interface access to trusted administrative networks.
- Harden administrative accounts with MFA and least privilege.
- Monitor administrative activity for unexpected interface content changes.
Validation and detection
- Inventory Cisco ISE deployments and exposed management interfaces.
- Confirm installed ISE versions against Cisco's advisory.
- Review administrative account access and recent credential-risk events.
- Check logs for suspicious administrative changes to interface content.
- Verify management access restrictions are enforced.
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-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 lookupCVE-2021-34759 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
- 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
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:H/UI:R/S:C/C:L/I:L/A:N1.72.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.8MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210901 Cisco Identity Services Engine Cross-Site Scripting 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 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.