Adaptive Security Appliance SoftwareOperating system · Cisco
CVE-2023-20264
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 implementation of Security Assertion Markup Language (SAML) 2.0 single sign-on (SSO) for remote access VPN in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to intercept the SAML assertion of a user who is authenticating to a remote access VPN session. This vulnerability is due to insufficient validation of the login URL. An attacker could exploit this vulnerability by persuading a user to access a site that is under the control of the attacker, allowing the attacker to modify the login URL. A successful exploit could allow the attacker to intercept a successful SAML assertion and use that assertion to establish a remote access VPN session toward the affected device with the identity and permissions of the hijacked user, resulting in access to the protected network.
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 confidenceA vulnerability in the SAML 2.0 SSO implementation for remote access VPN in Cisco ASA and FTD software allows unauthenticated remote attackers to intercept SAML assertions due to insufficient validation of the login URL. Attackers can hijack a user's VPN session by persuading them to visit a malicious site that modifies the login URL.
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
Adaptive Security Appliance SoftwareOperating system
>= 9.18.1, <= 9.18.3.46>= 9.19.1.5, <= 9.19.1.12
Secure Firewall Threat DefenseApplication
= 7.2.4CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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.
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Identify product type and versionRun 'show version' or 'show module' command on the device to determine if it is Cisco ASA or Firepower Threat Defense (FTD) and note the exact software version number.Affected if The device is a Cisco ASA or FTD and the installed version falls within 9.18.1 to 9.18.3.46, 9.19.1.5 to 9.19.1.12, or exactly 7.2.4.
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Confirm SAML SSO is configured for VPNRun 'show run all webvpn' and look for 'saml idp' configuration under the remote access VPN webvpn configuration, or check the group policy for 'saml' authentication settings.Affected if SAML-based authentication is configured as the SSO method for AnyConnect or clientless VPN remote access.
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Inspect SAML IdP metadata and login URLRun 'show running-config webvpn saml idp' to display the configured Identity Provider metadata and examine the IdP URL settings for any unexpected or suspicious entries.Affected if The IdP URL in the SAML configuration points to an untrusted or unrecognized domain, or the configuration shows signs of modification.
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Check for duplicate SAML IdP configurationsRun 'show run | include saml idp' to list all SAML IdP configurations and verify there are no duplicate or unauthorized IdP entries.Affected if Multiple SAML IdP configurations exist where only one was intentionally configured, indicating potential tampering.
The environment is affected if the device runs Cisco ASA software versions 9.18.1-9.18.3.46 or 9.19.1.5-9.19.1.12, or FTD version 7.2.4, AND SAML SSO authentication is enabled for remote access VPN.
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.
From vendor dataApply the relevant Cisco security updates for ASA and FTD software. Review and validate SAML SSO configurations to ensure proper login URL validation.
Fix this in Adaptive Security Appliance Software
Scoped from the published advisory
- Consultation4.0 h
- Implementation6.0 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 $4,544.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-20264 — 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-2023-20264 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
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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