CVE-2023-20269
A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct a brute force attack in an attempt to identify valid username and password combinations or an authenticated, remote attacker to establish a clientless SSL VPN session with an unauthorized user. This vulnerability is due to improper separation of authentication, authorization, and accounting (AAA) between the remote access VPN feature and the HTTPS management and site-to-site VPN features. An attacker could exploit this vulnerability by specifying a default connection profile/tunnel group while conducting a brute force attack or while establishing a clientless SSL VPN session using valid credentials. A successful exploit could allow the attacker to achieve one or both of the following: Identify valid credentials that could then be used to establish an unauthorized remote access VPN session. Establish a clientless SSL VPN session (only when running Cisco ASA Software Release 9.16 or earlier). Notes: Establishing a client-based remote access VPN tunnel is not possible as these default connection profiles/tunnel groups do not and cannot have an IP address pool configured. This vulnerability does not allow an attacker to bypass authentication. To successfully establish a remote access VPN session, valid credentials are required, including a valid second factor if multi-factor authentication (MFA) is configured. Cisco will release software updates that address this vulnerability. There are workarounds that address this vulnerability.
- CVSS
- 5.0Mediumscored by the publisher (CNA)
- Exploited in the wild
- Yes, in CISA KEV since 13 Sept 2023CISA deadline for US federal agencies: 4 Oct 2023known use in ransomware campaigns
- EPSS
- 26.6%chance of exploitation in the next 30 daystop 2% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 6 Sept 2023analysed here 12 Nov 2026
Do first. Apply mitigations per vendor instructions for group-lock and vpn-simultaneous-logins or discontinue use of the product for unsupported devices. (CISA's required action for this KEV entry)
Summary
Triage
- Attack surface
- Server-side
- Exploitable
- At runtime
- Attack vector
- network
- Can a WAF block it?
- Partly. See why
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Cisco Cisco Adaptive Security Appliance (ASA) Software | 9.8.19.8.1.59.8.1.79.8.29.8.2.89.8.2.149.8.2.159.8.2.179.8.2.209.8.2.249.8.2.269.8.2.289.8.2.339.8.2.359.8.2.389.8.3.89.8.3.119.8.3.149.8.3.169.8.3.189.8.3.219.8.39.8.3.269.8.3.299.8.49.8.4.39.8.4.79.8.4.89.8.4.109.8.4.129.8.4.159.8.4.179.8.4.259.8.4.209.8.4.229.8.4.269.8.4.299.8.4.329.8.4.339.8.4.349.8.4.359.8.4.399.8.4.409.8.4.419.8.4.439.8.4.449.8.4.459.8.4.469.8.4.489.12.19.12.1.29.12.1.39.12.29.12.2.49.12.2.59.12.2.99.12.39.12.3.29.12.3.79.12.49.12.3.129.12.3.99.12.2.19.12.4.29.12.4.49.12.4.79.12.4.109.12.4.139.12.4.89.12.4.189.12.4.249.12.4.269.12.4.299.12.4.309.12.4.359.12.4.379.12.4.389.12.4.399.12.4.409.12.4.419.12.4.479.12.4.489.12.4.509.12.4.529.12.4.549.12.4.559.12.4.569.12.4.589.14.19.14.1.109.14.1.69.14.1.159.14.1.199.14.1.309.14.29.14.2.49.14.2.89.14.2.139.14.2.159.14.39.14.3.19.14.3.99.14.3.119.14.3.139.14.3.189.14.3.159.14.49.14.4.69.14.4.79.14.4.129.14.4.139.14.4.149.14.4.159.14.4.179.14.4.229.14.4.239.15.19.15.1.79.15.1.109.15.1.159.15.1.169.15.1.179.15.1.19.15.1.219.16.19.16.1.289.16.29.16.2.39.16.2.79.16.2.119.16.2.139.16.2.149.16.39.16.3.39.16.3.149.16.3.159.16.3.199.16.3.239.16.49.16.4.99.16.4.149.16.4.189.16.4.199.16.4.279.16.4.389.17.19.17.1.79.17.1.99.17.1.109.17.1.119.17.1.139.17.1.159.17.1.209.17.1.309.18.19.18.1.39.18.29.18.2.59.18.2.79.18.2.89.18.39.18.3.399.18.3.469.18.3.539.18.3.559.19.19.19.1.59.19.1.99.19.1.129.19.1.18Vendor says fixed in: not stated | |
| Cisco Cisco Firepower Threat Defense Software | 6.2.36.2.3.16.2.3.26.2.3.36.2.3.46.2.3.56.2.3.66.2.3.76.2.3.86.2.3.106.2.3.116.2.3.96.2.3.126.2.3.136.2.3.146.2.3.156.2.3.166.2.3.176.2.3.186.6.06.6.0.16.6.16.6.36.6.46.6.56.6.5.16.6.5.26.6.76.6.7.16.4.06.4.0.16.4.0.36.4.0.26.4.0.46.4.0.56.4.0.66.4.0.76.4.0.86.4.0.96.4.0.106.4.0.116.4.0.126.4.0.136.4.0.146.4.0.156.4.0.166.7.06.7.0.16.7.0.26.7.0.37.0.07.0.0.17.0.17.0.1.17.0.27.0.2.17.0.37.0.47.0.57.0.67.1.07.1.0.17.1.0.27.1.0.37.2.07.2.0.17.2.17.2.27.2.37.2.47.2.4.17.2.57.3.07.3.17.3.1.17.4.0Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- cisco:adaptive_security_appliance_software
- cisco:secure_firewall_threat_defense
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Partly. The attack involves sending HTTP(S) requests to the VPN feature with specific parameters to brute force credentials or establish unauthorized sessions. These requests are unusual because they specify default connection profiles or tunnel groups, which normal users typically do not use this way, allowing partial filtering by a WAF. A custom WAF rule can filter requests specifying a default connection profile/tunnel group during authentication attempts, but attackers can vary the request. No tracked WAF vendor has published a rule for this CVE yet.
What a custom rule would match: requests specifying a default connection profile/tunnel group during authentication attempts
Also consider: patch · custom WAF rule · per-resource ACL
Based on an AI reading of the CVE description, and no vendor rule found yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 13 Sept 2023. Known use in ransomware campaigns.
- CISA due date
- 4 Oct 2023, the remediation deadline for US federal agencies
- CISA required action
- Apply mitigations per vendor instructions for group-lock and vpn-simultaneous-logins or discontinue use of the product for unsupported devices.
- Public exploit code
- None on record in Exploit-DB, Metasploit, Nuclei templates or PoC-in-GitHub.
- CISA SSVC
- exploitation active, automatable no, technical impact partialAssessed by CISA 7 Sept 2023 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Timeline
- 6 Sept 2023Published
- 7 Sept 2023CISA SSVC assessment: exploitation activesame day later
- 13 Sept 2023Added to CISA KEV (exploited in the wild)6 days later
- 4 Oct 2023CISA remediation due date (US federal agencies)21 days later
- 6 Aug 2026CVE record last updated1,037 days (about 3 years) later
- 12 Nov 2026Analysed by vulneraibility.com98 days (about 3 months) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | LowThe attacker needs basic user privileges. | The attacker needs basic user privileges. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | ChangedImpact crosses a security boundary into other components. | Impact crosses a security boundary into other components. |
| Confidentiality | NoneNo data disclosure. | No data disclosure. |
| Integrity | LowLimited modification possible. | Limited modification possible. |
| Availability | NoneThe service stays up. | The service stays up. |
Common questions
Is CVE-2023-20269 being exploited?
Yes. CVE-2023-20269 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2023-20269?
CVE-2023-20269 is rated Medium with a CVSS score of 5.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2023-20269?
Yes. A fix has been recorded for CVE-2023-20269. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2023-20269 affect?
CVE-2023-20269 affects cisco:adaptive_security_appliance_software, cisco:secure_firewall_threat_defense. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
2 references in the CVE record, grouped by the tags the record gives them.
Other links (2)
- sec.cloudapps.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ravpn-auth-8LyfCk
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-20269
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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