Secure Firewall Threat DefenseApplication · Cisco
CVE-2020-3259
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceMemory disclosure vulnerability in Cisco ASA and FTD web services interface. An unauthenticated remote attacker can send crafted GET requests with invalid URLs to retrieve memory contents due to a buffer tracking issue. Only affects devices with specific AnyConnect or WebVPN configurations enabled.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Secure Firewall Threat DefenseApplication
>= 6.2.3, < 6.2.3.16>= 6.3.0, < 6.3.0.6>= 6.4.0, < 6.4.0.9>= 6.5.0, < 6.5.0.5
Adaptive Security Appliance SoftwareOperating system
>= 9.8, < 9.8.4.20>= 9.9, < 9.9.2.67>= 9.10, < 9.10.1.40>= 9.12, < 9.12.3.9>= 9.13, < 9.13.1.10CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify product and firmware versionRun 'show version' on the Cisco ASA CLI or 'show version' on the FTD CLI. Note the software version displayed.Affected if The software version falls within any of these ranges: FTD: 6.2.3 through <6.2.3.16, 6.3.0 through <6.3.0.6, 6.4.0 through <6.4.0.9, 6.5.0 through <6.5.0.5; ASA: 9.8 through <9.8.4.20, 9.9 through <9.9.2.67, 9.10 through <9.10.1.40, 9.12 through <9.12.3.9, 9.13 through <9.13.1.10
-
Check if WebVPN is enabledRun 'show running-config webvpn' or 'show run webvpn' on the device CLI.Affected if The command returns configuration output indicating webvpn is enabled (not an error that webvpn is not configured)
-
Check if AnyConnect is enabledRun 'show running-config anyconnect' or 'show run anyconnect' on the device CLI.Affected if The command returns configuration output showing anyconnect is enabled, including any anyconnect-profile or clientless SSL VPN settings
The device is affected only if it runs a vulnerable ASA or FTD version AND has either WebVPN or AnyConnect enabled, as the vulnerability requires these specific VPN configurations to be active.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped6.2.3.166.3.0.66.4.0.9
Apply the relevant Cisco security updates for ASA and FTD software. Identify and review all AnyConnect/WebVPN configurations to confirm exposure, as the vulnerability affects only specific deployments.
Cisco ASA: 9.8.4.20+, 9.9.2.67+, 9.10.1.40+, 9.12.3.9+ | Cisco FTD: 6.2.3.16+, 6.3.0.6+, 6.4.0.9+, 6.5.0.5+
- 1. Identify the currently installed Cisco ASA or FTD software version using 'show version' command
- 2. Determine which product line (ASA or FTD) and version branch is in use from the affected version ranges
- 3. For Firepower Threat Defense: upgrade to version 6.2.3.16, 6.3.0.6, 6.4.0.9, or 6.5.0.5 (or later) depending on the current branch
- 4. For Adaptive Security Appliance: upgrade to version 9.8.4.20, 9.9.2.67, 9.10.1.40, or 9.12.3.9 (or later) depending on the current branch
- 5. Download the appropriate software from Cisco (requires valid SMARTnet contract)
- 6. Upload the new image to the device and install using 'install pkg file' command for FTD or standard ASA upgrade procedure
- 7. Reload the device after upgrade completes
- 8. Verify the new version is installed using 'show version'
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Secure Firewall Threat Defense
Exploited in the wild — priority engagement
- Consultation3.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,648.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3259 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-3259 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data