How severe is CVE-2020-3259?

CVE-2020-3259 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-3259?

Affected package information for CVE-2020-3259 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2020-3259?

No fixed version has been published for CVE-2020-3259 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2020-3259 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2020-3259, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-3259?

CVE-2020-3259 has an EPSS (Exploit Prediction Scoring System) score of 69.7%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2020-3259 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2020-3259 (Cisco ASA and FTD Information Disclosure Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2024-02-15. CISA required all US federal civilian agencies to remediate this vulnerability by 2024-03-07. The required action was: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2020-3259?

CVE-2020-3259 is classified as Information Exposure (CWE-200). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2020-3259?

CVE-2020-3259 affects cisco adaptive security appliance software; cisco firepower threat defense. Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2020-3259 published, and has it been updated?

CVE-2020-3259 was published on May 6, 2020 and was last updated on October 28, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2020-3259: Adaptive Security Appliance Software Information…

EPSS Exploitation Probability

via FIRST.org ↗

69.7%probability of exploitation in next 30 days

High Risk99th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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.

Affected Products

2 products · 9 configurations

OS

adaptive security appliance softwarecisco

≥ 9.13 && < 9.13.1.10

range

Application

firepower threat defensecisco

≥ 6.5.0 && < 6.5.0.5

range

Frequently Asked Questions

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 a

O3 Security · Impact-Aware SCA

Is CVE-2020-3259 in your stack?

O3 detects CVE-2020-3259 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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