What’s Vulnerable › Vulnerabilities

CVE-2020-3246: Cisco Umbrella Carriage Return Line Feed Injection Vulnerability

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-05-06 · updated 2026-06-17
• Weakness: CWE-93

Description

A vulnerability in the web server of Cisco Umbrella could allow an unauthenticated, remote attacker to perform a carriage return line feed (CRLF) injection attack against a user of an affected service. The vulnerability is due to insufficient validation of user input. An attacker could exploit this vulnerability by persuading a user to access a crafted URL. A successful exploit could allow the attacker to inject arbitrary HTTP headers into valid HTTP responses sent to the browser of the user.

Affected products

• Cisco Umbrella Insights Virtual Appliance: all versions

References

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-umbrella-head-inject-n4QArJH
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-umbrella-head-inject-n4QArJH

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