CVE-2020-3259
7.5, high Known exploited Used in ransomwareCisco ASA and FTD Information Disclosure Vulnerability
- CVSS
- 7.5, high high CVSS v3.1
- EPSS, next 30 days
- 72% higher than 99.4% of scored CVEs
- Exploitation
- Confirmed in the wild
- Published
- 6 May 20206 years ago
Known exploited
CISA added this to the Known Exploited Vulnerabilities Catalog on 15 Feb 2024 and links it to ransomware activity. US federal agencies had to remediate by 7 Mar 2024, a deadline that has passed.
Required action. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Description
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, which could lead to the disclosure of confidential information. The vulnerability is due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. An attacker could exploit this vulnerability by sending a crafted GET request to the web services interface. A successful exploit could allow the attacker to retrieve memory contents, which could lead to the disclosure of confidential information. Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.
Details
- Vendor
- Cisco
- Product
- Cisco Adaptive Security Appliance (ASA) Software
- Weakness
- CWE-200 (opens in a new tab)
- Status
- Analyzed
- Updated
- 12 Aug 2026
- Assigner
- psirt@cisco.com
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
References 2
The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.
Other Cisco CVEs
Every Cisco CVE we holdSame vendor in what we hold, not a known link between the flaws.
- CVE-2026-76519 Cisco Secure Email Gateway Relative Path Traversal Vulnerability KEV EPSS 2% 9.8, critical
- CVE-2026-76504 Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability KEV EPSS 2% 9.8, critical
- CVE-2026-76460 Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability KEV EPSS 14% 10, critical
- CVE-2026-76461 Cisco Secure Email Gateway SQL Injection Vulnerability KEV EPSS 30% 9.8, critical
- CVE-2026-20349 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability KEV EPSS 1% 8.6, high
- CVE-2026-20316 Cisco Secure Firewall Management Center Use of Hard-coded Password Vulnerability KEV EPSS 35% 5.3, medium
- CVE-2026-20262 Cisco Catalyst SD-WAN Manager Directory or Path Traversal Vulnerability KEV EPSS 28% 6.5, medium
- CVE-2026-20245 Cisco Catalyst SD-WAN Manager Improper Encoding or Escaping of Output Vulnerability KEV EPSS 25% 7.8, high
Beyond this page
Is CVE-2020-3259 in your network?
This page tells you how dangerous CVE-2020-3259 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.
CVE-2020-3259 is in the CISA catalogue of exploited vulnerabilities: attackers are already exploiting it.
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EXYS7600 OCELOT
Find it before attackers do
Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2020-3259 comes with the devices to patch.
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EXYS7950 KONDRA
Detect it if it's exploited
Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.
Learn more about EXYS7950 KONDRA
Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.