CVE-2020-3561: cisco adaptive_security_appliance CRLF Injection

Vulnerability summary

CVE-2020-3561 is a medium (CVSS 4.7) CRLF Injection vulnerability in cisco adaptive_security_appliance. EPSS estimates a 1.29% chance of exploitation in the next 30 days, higher than 69.7% of scored vulnerabilities.

Timeline

1. 21-10-2020
   PublishedVulnerability first disclosed.
2. 13-11-2024
   Last modifiedVulnerability information updated.

Description

A vulnerability in the Clientless SSL VPN (WebVPN) of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to inject arbitrary HTTP headers in the responses of the affected system. The vulnerability is due to improper input sanitization. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to conduct a CRLF injection attack, adding arbitrary HTTP headers in the responses of the system and redirecting the user to arbitrary websites.

• CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.
• CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.