CVE-2020-3259
Published: February 15, 2024
Official Description
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an information disclosure vulnerability. An attacker could retrieve memory contents on an affected device, which could lead to the disclosure of confidential information due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. This vulnerability affects only specific AnyConnect and WebVPN configurations.
CISA KEV Advisory
Cisco ASA and FTD Information Disclosure Vulnerability
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an information disclosure vulnerability. An attacker could retrieve memory contents on an affected device, which could lead to the disclosure of confidential information due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. This vulnerability affects only specific AnyConnect and WebVPN configurations.
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Risk Analysis
This information disclosure vulnerability in Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) allows an attacker to retrieve memory contents by sending invalid URLs to the web services interface. With an EPSS score of 0.69725 and confirmed exploitation in CISA's KEV, this flaw presents a significant risk of confidential information disclosure.
This vulnerability is actively exploited in the wild. It is remotely exploitable by sending specially crafted invalid URLs to the device's web services interface, specifically affecting certain AnyConnect and WebVPN configurations.
Cisco ASA and FTD users should apply all available security patches to address the buffer tracking issue. Review and secure AnyConnect and WebVPN configurations to minimize exposure.
Technical Analysis
CVE-2020-3259 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-2020-3259 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 (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-3259 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