Exploited CVEs / Cisco / CVE-2020-3259

CVE-2020-3259

Cisco ASA and FTD Information Disclosure Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted, and the vulnerability is known to be used in ransomware campaigns. Federal agencies were required to remediate by 2024-03-07 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Cisco Security Advisories (PSIRT), linked below.

HighCISA KEVRansomware

Actively exploited Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) vulnerability, High severity, CVSS 7.5. Added to the CISA KEV catalog 2024-02-15.

Senserva AI read on CVE-2020-3259CISA required actionOfficial fix for CVE-2020-3259Admin questions

Risk summary

CVSS base
7.5
EPSS exploit probability
69%
Severity
High
Added to KEV
2024-02-15
CISA due date
2024-03-07 (past due)
Patch immediately
Exploited in the wild and used in ransomware campaigns.
The fix ships from the vendor: Cisco Security Advisories (PSIRT).
Do this now: Move this ahead of everything else in the queue, then verify the fix actually landed on every exposed device.

Updated July 27, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Senserva AI Opinion for CVE-2020-3259

Ransomware operators found new life in this Cisco ASA and FTD information disclosure flaw: CISA added it to the KEV catalog in February 2024, four years after disclosure, citing active exploitation. The bug lets attackers retrieve memory contents from the device, disclosing confidential information that can assist further access. Firewalls running years-old ASA or FTD code remain exposed at the exact point attackers want to enter.

Do this: Upgrade ASA and FTD software past the CVE-2020-3259 fix and rotate VPN credentials that predate the patch.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2020-3259

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

Full tracking and change history for CVE-2020-3259

Published
2024-02-15
Last revised
2024-02-15
Changes tracked
1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

CISA required action

Federal (BOD 22-01) remediation due date: 2024-03-07 (past due).

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Official fix for CVE-2020-3259

The authoritative fix and affected-version list are published by the vendor. Find the Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) advisory on Cisco Security Advisories (PSIRT).

Common questions about CVE-2020-3259

Is CVE-2020-3259 actively exploited?

Yes. CVE-2020-3259 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2024-02-15, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 69%. CISA also reports it is known to be used in ransomware campaigns.

What is the CISA deadline and required action for CVE-2020-3259?

CISA set the federal (BOD 22-01) remediation due date at 2024-03-07, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

What fixes CVE-2020-3259?

The authoritative fix is in the vendor advisory: see Cisco Security Advisories (PSIRT) for the patched Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2020-3259?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2020-3259's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

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Lexicon: the terms on this page
CVE
Common Vulnerabilities and Exposures. A unique ID for one publicly known vulnerability, such as CVE-2025-1234.
KB
Microsoft Knowledge Base article. The identifier for a specific Microsoft update.
KEV
CISA Known Exploited Vulnerabilities. CVEs confirmed exploited in the wild. Fix these first.
CVSS
Common Vulnerability Scoring System. A standardized Severity score from 0 to 10.
EPSS
Exploit Prediction Scoring System. The probability a CVE will be exploited in the next 30 days.
MSRC
Microsoft Security Response Center. Microsoft's Patch Tuesday advisories and KB-to-CVE mapping.
NVD
National Vulnerability Database (NIST). Authoritative CVE metadata and CVSS scores.
Ransomware
The vulnerability is linked to known ransomware activity.
Reference: Microsoft CVE and vulnerability management, the full CVE-to-patch lookup ranked by real-world risk, and the Microsoft patching guide, how Intune, Windows Autopatch, Defender, and Azure Update Manager fit together.
Data notice: this page, the feeds, and the API are provided as is, for informational purposes only, without warranty of any kind. Senserva, LLC does not guarantee the accuracy, completeness, or timeliness of third-party data (MSRC, NVD, CISA KEV, EPSS) and accepts no liability for actions taken based on it; verify against the authoritative vendor advisory before acting. Built daily with Senserva Trustworthy AI. All use of this data is subject to the Senserva EULA.