CVE-2020-3452
Published: November 3, 2021
Official Description
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an improper input validation vulnerability when HTTP requests process URLs. An attacker could exploit this vulnerability by sending a crafted HTTP request containing directory traversal character sequences to an affected device. A successful exploit could allow the attacker to view arbitrary files within the web services file system on the targeted device.
CISA KEV Advisory
Cisco ASA and FTD Read-Only Path Traversal Vulnerability
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an improper input validation vulnerability when HTTP requests process URLs. An attacker could exploit this vulnerability by sending a crafted HTTP request containing directory traversal character sequences to an affected device. A successful exploit could allow the attacker to view arbitrary files within the web services file system on the targeted device.
Apply updates per vendor instructions.
Risk Analysis
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) devices are vulnerable to an improper input validation flaw when processing HTTP requests, allowing directory traversal. An attacker can view arbitrary files on the web services file system. The high EPSS score of 0.94452 indicates a very high likelihood of exploitation, making this an urgent concern. This vulnerability is actively exploited.
This vulnerability is actively exploited in the wild and is included in CISA's KEV catalog. An attacker can exploit this remotely by sending crafted HTTP requests.
Apply the security updates from Cisco for ASA and FTD to fix the improper input validation vulnerability. Implement strict access controls and monitor HTTP traffic for suspicious patterns.
Technical Analysis
CVE-2020-3452 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2020-3452 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-3452 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1