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CVE Record

CVE-2021-34751: Cisco Firepower Management Center Software Configuration Information Disclosure Vulnerability

A vulnerability in the administrative web-based GUI configuration manager of Cisco Firepower Management Center (FMC) Software could allow an authenticated, remote attacker to access sensitive configuration information. The attacker would require low privilege credentials on an affected device. This vulnerability exists because of improper encryption of sensitive information stored within the GUI configuration manager. An attacker could exploit this vulnerability by logging into the GUI of Cisco FMC Software and navigating to certain sensitive configurations. A successful exploit could allow the attacker to view sensitive configuration parameters in clear text.Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.[[Publication_URL{Layout()}]]This advisory is part of the October 2021 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. For a complete list of the advisories and links to them, see . 

MediumCVSS 4.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

A low-privileged Cisco Firepower Management Center user could view sensitive configuration details in clear text through the web GUI. This is an information disclosure issue, not remote code execution. Cisco says software updates address it and no workaround is available.

Executive priority

Treat as a moderate-priority confidentiality risk. It is most urgent where many users have FMC access or where configuration secrets could enable broader operational impact. Patch during the next appropriate maintenance window after confirming affected versions.

Technical view

CVE-2021-34751 affects Cisco FMC Software's administrative web-based GUI configuration manager. Improper encryption of sensitive stored configuration information can allow an authenticated remote attacker with low privileges to access sensitive configuration parameters in clear text. CVSS 3.1 is 4.3: network-accessible, low complexity, privileges required, confidentiality impact only.

Likely exposure

Exposure is limited to environments running affected Cisco FMC Software where low-privileged users can authenticate to the FMC web GUI. The supplied sources do not enumerate affected or fixed versions, so asset owners must confirm applicability against Cisco's advisory.

Exploitation context

The provided sources describe an authenticated, remote attack requiring low-privilege credentials and GUI access. CISA KEV status is false in the bundle, and no cited source states active exploitation. Evidence does not support claiming public exploitation.

Researcher notes

The core weakness is CWE-317: cleartext storage of sensitive information in a GUI configuration manager context. The bundle confirms patch availability and no workaround, but omits version ranges and fixed releases. Avoid expanding scope beyond Cisco FMC Software without vendor evidence.

Mitigation direction

  • Apply Cisco software updates identified in the vendor advisory.
  • Do not rely on workarounds; Cisco states none address this issue.
  • Restrict FMC GUI access to authorized administration networks.
  • Review low-privileged FMC accounts and remove unnecessary access.
  • Check Cisco guidance for affected and fixed release details.

Validation and detection

  • Inventory Cisco FMC deployments and software versions.
  • Compare deployed versions against the Cisco advisory.
  • Confirm FMC web GUI exposure is limited to trusted networks.
  • Review FMC user roles for unnecessary low-privileged accounts.
  • Check audit logs for unusual authenticated GUI access.
Prepared
Confidence
medium
Sources
3

Public sources used

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 · low confidence lookup

CWE-317: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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.

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cve · low confidence lookup

CVE-2021-34751 mapping review

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

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
4.3 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/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
4.3CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N2.81.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

4.3Medium
CVSS 3.1 vector shape for CVE-2021-34751Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/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 Firepower Management CenterN/AListed
Weakness

CWE details

CWE-317

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-317 · source CWE mapping

Cleartext Storage of Sensitive Information in GUI

Cleartext Storage of Sensitive Information in GUI represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs