CVE-2020-3246
Cisco Umbrella Carriage Return Line Feed Injection Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.7
Cisco Umbrella Carriage Return Line Feed Injection Vulnerability
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.
- Record
CVE-2020-3246- CVSS 3.0
- 4.7 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N - Weakness
- CWE-93
- Updated
- 2026-11-02
EUVDEUVD-2020-24517
4.7
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.
- Record
EUVD-2020-24517- CVSS 3.0
- 4.7 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-j53q-vx25-fmqm No score
A vulnerability in the web server of Cisco Umbrella could allow an unauthenticated, remote...
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.
- Record
GHSA-j53q-vx25-fmqm- Updated
- 2026-11-02
NVD
4.3
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.
- Record
CVE-2020-3246- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - CVSS 3.0
- 4.7 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-93, CWE-74
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-3246 is a medium vulnerability (CVSS 4.7) in Cisco Umbrella, published May 6, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.90%, the 59th percentile. No source names a fixed version.