Security readout for executives and security teams
Plain-English summary
This flaw can let a remote attacker log in to affected Cisco Enterprise NFVIS devices as an administrator without valid credentials. For executives, the business risk is direct administrative takeover of network virtualization infrastructure, with potential confidentiality, integrity, and availability impact.
Executive priority
Treat as urgent for any organization running Cisco Enterprise NFVIS, especially if management or authentication surfaces are reachable beyond tightly controlled networks. Confirm exposure quickly, then remediate according to Cisco guidance.
Technical view
CVE-2021-34746 affects the TACACS+ AAA feature in Cisco Enterprise NFV Infrastructure Software. Incomplete validation of user-supplied input passed to an authentication script can allow parameter injection in an authentication request, bypassing authentication and granting administrator access.
Likely exposure
Exposure is most likely where Cisco Enterprise NFVIS is deployed and the TACACS+ AAA authentication path is reachable by untrusted or broad networks. The source bundle does not provide affected version ranges, so version-specific exposure must be confirmed with Cisco guidance.
Exploitation context
The CVSS 3.1 score is 9.8 because exploitation is remote, low complexity, unauthenticated, and requires no user interaction. The provided bundle does not show CISA KEV listing or confirmed active exploitation, so active exploitation should not be assumed from these sources.
Researcher notes
The public description identifies authentication bypass through parameter injection into an authentication script in TACACS+ AAA. The source bundle does not include affected version ranges, exploit maturity, indicators of compromise, or exact remediation details beyond the vendor advisory reference.
Mitigation direction
- Inventory Cisco Enterprise NFVIS deployments and ownership.
- Determine whether TACACS+ AAA is enabled on NFVIS devices.
- Review Cisco's advisory for affected and fixed release guidance.
- Apply Cisco-supported updates or workarounds when confirmed by the advisory.
- Restrict NFVIS administrative access to trusted management networks where feasible.
Validation and detection
- Confirm Cisco Enterprise NFVIS presence in asset inventory.
- Check whether TACACS+ AAA is configured on each NFVIS device.
- Compare installed NFVIS versions against Cisco advisory guidance.
- Review logs for unexpected administrator logins or authentication anomalies.
- Verify management interfaces are not broadly internet reachable.
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-289: Exact CWE lookup
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Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-34746 mapping review
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Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20210901 Cisco Enterprise NFV Infrastructure Software Authentication Bypass VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
- https://github.com/orangecertcc/security-research/security/advisories/GHSA-gqx8-c4xr-c664CVE reference · x_refsource_MISC
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.
Authentication Bypass by Alternate Name
Authentication Bypass by Alternate Name represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.