# CVE-2020-3259: Cisco ASA and FTD Information Disclosure

> Unauthenticated remote attackers can retrieve memory contents via crafted requests, exposing confidential information in specific Cisco ASA and FTD configurations.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Yes, since 15 Feb 2024 (CISA KEV), used in ransomware
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 May 2020
- **Updated:** 12 Aug 2026
- **Also known as:** GHSA-vw99-pf8w-g3cw

## What is CVE-2020-3259?

CVE-2020-3259 is a high-severity vulnerability in Cisco Adaptive Security Appliance Software, published on 6 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2020-3259?

It affects 2 products.


Products: Cisco Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense.

## How do I fix CVE-2020-3259?

No fix has been published for CVE-2020-3259 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 7 Mar 2024.

## Is CVE-2020-3259 being exploited?

Yes. Attackers have exploited CVE-2020-3259 in the wild since at least 15 Feb 2024, including in ransomware campaigns.

## Other vulnerabilities in Cisco Adaptive Security Appliance Software

- [CVE-2025-20333](https://insights.sbomify.com/CVE-2025-20333/): Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow (critical 9.9, exploited in the wild)
- [CVE-2016-6366](https://insights.sbomify.com/CVE-2016-6366/): Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2026-20349](https://insights.sbomify.com/CVE-2026-20349/): Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection (high 8.6, exploited in the wild)
- [CVE-2024-20353](https://insights.sbomify.com/CVE-2024-20353/): Cisco ASA and FTD Denial of Service (high 8.6, exploited in the wild)
- [CVE-2016-6367](https://insights.sbomify.com/CVE-2016-6367/): Cisco Adaptive Security Appliance (ASA) CLI Remote Code Execution (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3259 and fix it if it is affected.

What it is: CVE-2020-3259 is a high-severity vulnerability in Cisco Adaptive Security Appliance Software, published on 6 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2020-3259 in the wild since at least 15 Feb 2024, including in ransomware campaigns.

Affected product: Cisco Adaptive Security Appliance Software. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-3259/ (Markdown: https://insights.sbomify.com/CVE-2020-3259/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3259
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3259
- OSV: https://osv.dev/vulnerability/CVE-2020-3259

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3259/
Summaries are generated and may contain mistakes; the official description above is the record.