Cisco ASA and FTD Information Disclosure Vulnerability
Cisco / Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
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.
- CVE identifier
- CVE-2020-3259
- Added to KEV
- Feb 15, 2024
- CISA catalog dueDate
- Mar 7, 2024
The dates above are catalog fields. The addition date does not establish when the vulnerability was discovered or first exploited. Confirm which requirements apply to your organisation separately.
Publisher's required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
This wording is attributed to the CISA snapshot. Verify current vendor guidance, affected versions and your deployment before applying changes.
Keep the signals separate.
- Ransomware use, as reported by CISA
- Known
- CVSS severity
- Not supplied by KEV
- EPSS probability
- 71.79%
EPSS score date: 2026-09-27T12:00:21Z. Percentile: 99.41%. Model version: v2026.06.15.
A dated estimate of exploitation probability over the following 30 days, not a severity score or a probability of a breach in your environment.
Inspect the EPSS source ↗“Unknown” ransomware use is an unknown source field, not proof that ransomware activity has not occurred.
Source notes
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-info-disclose-9eJtycMB; https://nvd.nist.gov/vuln/detail/CVE-2020-3259
Source & freshness
Source updated: Sep 27, 2026, 9:30 PM UTC
Successfully checked: Sep 27, 2026, 11:50 PM UTC
This snapshot is older than 36 hours. Check current publisher guidance.
Automated source record, not an editorial advisory or an independent discovery. No affected or fixed version is inferred, and no organisation-specific risk rating is generated.