CVE-2020-3259

Deeper analysis

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated remote attacker to retrieve memory contents on an affected device. The issue stems from a buffer tracking problem that occurs when the software parses invalid URLs requested through the interface, and it is limited to specific AnyConnect and WebVPN configurations. Successful exploitation results in disclosure of confidential information, reflected in the CVSS 7.5 score emphasizing high confidentiality impact without integrity or availability effects.

An attacker can exploit the flaw by sending a crafted GET request to the web services interface, enabling retrieval of memory contents without authentication or user interaction. This remote attack vector requires low attack complexity and grants direct access to potentially sensitive data stored in memory on the device.

The Cisco Security Advisory recommends applying the fixes and mitigations detailed in the advisory for affected ASA and FTD versions, including configuration changes or software updates to address the vulnerable AnyConnect and WebVPN setups. The vulnerability is also listed in the CISA Known Exploited Vulnerabilities Catalog, indicating confirmed real-world exploitation activity.