TI-2021-17321 Aliases CVE-2021-40126 GHSA-qh32-c3pp-x33g

Cisco Umbrella Email Enumeration Vulnerability

LOW 22CWE-210Published 2021-11-04 · Updated 2024-11-07

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Information disclosure
Confidentiality · integrity · availability: Low · None · None
Fix status: No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-209.

Summary

A vulnerability in the web-based dashboard of Cisco Umbrella could allow an authenticated, remote attacker to perform an email enumeration attack against the Umbrella infrastructure. This vulnerability is due to an overly descriptive error message on the dashboard that appears when a user attempts to modify their email address when the new address already exists in the system. An attacker could exploit this vulnerability by attempting to modify the user's email address. A successful exploit could allow the attacker to enumerate email addresses of users in the system.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00873 59th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Cisco	Cisco Umbrella Insights Virtual Appliance	all versions	—	No fix listed	CNA

Cisco Umbrella Insights Virtual Appliance VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:cisco:umbrella:-:::::::*	not specified by NVD	Vulnerable	Cisco

cpe:2.3:a:cisco:umbrella:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2021-40126
2026-10-03 Alias added: GHSA-qh32-c3pp-x33g

References

Advisory 1

20211103 Cisco Umbrella Email Enumeration Vulnerability

TI-2019-01430 Cisco Umbrella Dashboard Session Management Vulnerability CVSS 3.0HIGH 8.8
TI-2018-00394 Cisco Umbrella API Unauthorized Access Vulnerability CVSS 3.0CRITICAL 9.1
TI-2021-01201 Cisco Umbrella Link and CSV Formula Injection Vulnerabilities CVSS 3.1HIGH 8.6
TI-2021-01077 Cisco Umbrella Dashboard Packet Flood Vulnerability CVSS 3.1MEDIUM 5.3
TI-2021-01202 Cisco Umbrella Link and CSV Formula Injection Vulnerabilities CVSS 3.1MEDIUM 6.5
TI-2019-01417 Cisco Umbrella Cross-Site Scripting Vulnerability CVSS 3.1MEDIUM 6.1

See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences