Security readout for executives and security teams
Plain-English summary
Cisco FMC’s web management interface had weaknesses that could let a highly privileged attacker cause cross-site scripting or redirect a user through a malicious link. Business risk is moderate because exploitation needs high privileges and user interaction, but FMC manages security infrastructure, so exposed or poorly governed consoles deserve prompt review.
Executive priority
Treat this as a scheduled security-platform remediation item, not an emergency, unless FMC is broadly exposed or administrator accounts are weakly controlled. Prioritize version confirmation, access restriction, and vendor-directed updates because FMC is a sensitive control-plane system.
Technical view
CVE-2021-34764 covers Cisco Firepower Management Center web-interface XSS and open redirect issues. The CVSS 3.1 score is 4.8, with network reachability, low attack complexity, high privileges required, user interaction required, changed scope, and low confidentiality and integrity impact.
Likely exposure
Organizations using Cisco Firepower Management Center are the relevant population. Exposure is highest where the FMC management interface is reachable by broad internal users or the internet, and where privileged FMC accounts can be targeted into interacting with crafted content.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The vulnerability is constrained by high privilege requirements and user interaction, but successful abuse could affect trust in the management interface and enable limited data exposure or content manipulation.
Researcher notes
Evidence is incomplete for affected version ranges and specific fixed releases in the supplied bundle. Analysis is limited to the CVE metadata and Cisco advisory reference. Do not assume exploit availability or remediation details beyond checking Cisco’s published guidance.
Mitigation direction
- Review Cisco’s advisory for affected releases and fixed software guidance.
- Inventory all Cisco FMC deployments and their software versions.
- Restrict FMC management access to trusted administration networks.
- Enforce least privilege for FMC administrator accounts.
- Monitor Cisco security advisories for updated remediation details.
Validation and detection
- Confirm whether Cisco FMC is deployed in the environment.
- Compare deployed FMC versions against Cisco advisory applicability.
- Verify the management interface is not internet-accessible.
- Review FMC administrator account scope and necessity.
- Check security monitoring for suspicious FMC web-interface activity.
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-601: 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-2021-34764 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
- 20211027 Cisco Firepower Management Center Software Cross-Site Scripting and Open Redirect VulnerabilitiesCVE 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.
URL Redirection to Untrusted Site ('Open Redirect')
URL Redirection to Untrusted Site ('Open Redirect') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.