CVE-2020-3259

CVE-2020-3259 is a high-severity vulnerability in Cisco Secure Firewall Threat Defense with a CVSS 3.x base score of 7.5. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2024-02-15). The underlying weakness is classified as CWE-200.

Key facts

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.

Frequently asked questions

What is CVE-2020-3259?
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.
How severe is CVE-2020-3259?
CVE-2020-3259 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-3259 being actively exploited?
Yes. CVE-2020-3259 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-02-15, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2020-3259?
CVE-2020-3259 primarily affects Cisco Secure Firewall Threat Defense. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3259?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2020-3259 have an EU (EUVD) identifier?
Yes. CVE-2020-3259 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-24530. It is also flagged as exploited in the EUVD (since 2024-02-15).
When was CVE-2020-3259 published?
CVE-2020-3259 was published on 2020-05-06 and last updated on 2026-08-12.

References

Affected products (2)

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