Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2020-3259

Cisco Adaptive Security Appliance (ASA) Software Information Disclosure

Cisco Adaptive Security Appliance (ASA) Software · affected before 6.2.3.16

Watch CVE-2020-3259 Browse KEV feed
Severity
CVSS 7.5 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
71.5%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2020-3259 is an unauthenticated vulnerability affecting Cisco Adaptive Security Appliance (ASA) Software. A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Cisco Adaptive Security Appliance (ASA) Software affected before 6.2.3.16.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Cisco Adaptive Security Appliance (ASA) Software Information Disclosure

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.

cisco Affected
firepower_threat_defense
Before 6.2.3.16 Before 6.3.0.6 Before 6.4.0.9 Before 6.5.0.5
cisco Affected
adaptive_security_appliance_software
Before 9.8.4.20 Before 9.9.2..67 Before 9.10.1.40 Before 9.12.3.9 Before 9.13.1.10
View vendor advisory (opens in new tab)
Published
06 May 2020
Exploitation Reported
15 Feb 2024
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

edge malware nessus_scanner ransomware cisa

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 15 Feb 2024

A trusted third party reported exploitation.

Used in malware

CISA

Recorded 15 Feb 2024

Malware families have been linked to exploitation of this CVE.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2024-02-15 00:00 UTC
CVE 2026-08-12 04:21 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nessus https://www.tenable.com/plugins/nessus/137659 02 Jun 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

7.5 High

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

71.5%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Exposure of Sensitive Information to an Unauthorized Actor CWE-200

Recent mention · The Hacker News

ThreatsDay: AI Secrets Leak, PingCAP Source Theft, Signal Hang-Up Flaw, Laravel Auth Bypass + 21 More

Ravie LakshmananOct 22, 2026Hacking News / Cybersecurity News This week has already been rough for cybersecurity. Critical PHP and GitLab RCE flaws, serious Linux security bugs, compromised eMudhra certificates, a Node.js RCE flaw, a hacked LiteLLM release, and hundreds of...

Read full advisory

All CVSS Scores

CVSS v3.1 7.5 High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v3.0 7.5 High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v2.0 5.0 Medium

AV:N/AC:L/Au:N/C:P/I:N/A:N

All Mentions

Recent mention · The Hacker News

ThreatsDay: AI Secrets Leak, PingCAP Source Theft, Signal Hang-Up Flaw, Laravel Auth Bypass + 21 More

The Hacker News · 22 Oct 2026

Ravie LakshmananOct 22, 2026Hacking News / Cybersecurity News This week has already been rough for cybersecurity. Critical PHP and GitLab RCE flaws, serious Linux security bugs, compromised eMudhra certificates, a Node.js RCE flaw, a hacked LiteLLM release, and hundreds of hijacked Tor relays. That's a lot to deal with in just a few days. And the week isn't even over yet. But those big headlines are only half the story. Stolen passwords, exposed databases, broken login checks, and trusted tools being turned against their users are causing trouble too. Some attacks are clever. Others work...

Recent mention · The Record

FBI says SafePay ransomware gang ‘among most active’ with more than 600 victims since 2024

The Record · 20 Oct 2026

The FBI and cyber agencies in the UK and Germany said SafePay is targeting businesses and critical infrastructure by guessing passwords, exploiting vulnerabilities and using phishing attacks.

Timeline

From disclosure to observed exploitation

  1. 04:21 UTC

    KEV confirmed by CVE

    Exploitation attested by an external source

  2. 09:26 UTC

    Nessus plugin available

    Scanner coverage available

  3. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  4. 00:00 UTC

    First public exploitation report

    Exploit observed in malware

  5. 16:41 UTC

    CVE published

    Vulnerability disclosed publicly

  6. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

Start 14-day Pro trial Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2020-3259

Sample API response 
{
  "cve_id": "CVE-2020-3259",
  "confidence": "Confirmed",
  "cvss_score": 7.5,
  "cvss_estimated": false,
  "epss_score": 0.715,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}