Security readout for executives and security teams
Plain-English summary
Cisco Firepower Management Center has an authenticated directory traversal flaw in its web management interface. A user with valid device credentials could read or write arbitrary files on the appliance. Because FMC manages security infrastructure, compromise could affect confidentiality and integrity of management data and device operations.
Executive priority
Treat this as high priority for environments using Cisco FMC. It is not described as publicly exploited here, but the ability to read or write arbitrary files on a security management platform creates material operational risk.
Technical view
CVE-2021-34762 is caused by insufficient HTTPS URL input validation in Cisco FMC Software. An authenticated remote attacker with low privileges could submit a crafted HTTPS request containing traversal sequences, leading to arbitrary file read or write. CVSS 3.1 is 8.1: network-accessible, low complexity, privileges required, no user interaction.
Likely exposure
Exposure is limited to Cisco Firepower Management Center deployments where authenticated users can reach the web-based management interface. The source bundle does not provide affected version ranges, so teams must confirm release exposure through Cisco’s advisory or asset records.
Exploitation context
The source bundle does not show active exploitation, and KEV is false. Exploitation requires valid device credentials, but the potential impact is significant because successful abuse can read or write arbitrary files on a security management system.
Researcher notes
Evidence supports authenticated remote directory traversal via FMC’s web interface with arbitrary file read/write impact. The bundle lacks affected version detail, patch identifiers, and mitigation specifics beyond the Cisco advisory reference, so validation should be advisory-driven.
Mitigation direction
- Check Cisco’s advisory for affected releases and fixed software guidance.
- Restrict FMC management access to trusted administrative networks and users.
- Review FMC accounts and remove unnecessary or stale credentials.
- Monitor FMC for unexpected file integrity or configuration changes.
Validation and detection
- Inventory all Cisco FMC instances and record software versions.
- Compare deployed versions against the Cisco advisory’s affected release information.
- Confirm web management interfaces are not broadly reachable.
- Review authentication and administrative activity logs for unusual access patterns.
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
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CWE-26: Exact CWE lookup
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Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-34762 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
- High
- CVSS
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:L/UI:N/S:U/C:H/I:H/A:N2.85.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20211027 Cisco Firepower Management Center Software Authenticated Directory Traversal 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.
Path Traversal: '/dir/../filename'
Path Traversal: '/dir/../filename' represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.