CVE-2025-20333
Confirmed PUBLISHEDA vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense...
1 day faster than CISA KEV
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker with valid VPN user credentials could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute arbitrary code as root, possibly resulting in the complete compromise of the affected device.
- CVE Published
- Sep 25, 2025
- Exploitation Reported
- Jun 01, 2026
- CVSS
- 9.9 Critical
- EPSS
- 40.4%
Affected Versions
300 version rows · page 7 of 12
| Vendor | Product | Version | Status |
|---|---|---|---|
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.16.4.70 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.16.4.71 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.16.4.76 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.16.4.82 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.16.4.84 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.7 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.9 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.10 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.11 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.13 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.15 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.20 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.30 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.33 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.17.1.39 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.18.1 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.18.1.3 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.18.2 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.18.2.5 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.18.2.7 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.18.2.8 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.18.3 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.18.3.39 |
Affected |
| Cisco |
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
|
9.18.3.46 |
Affected |
CVE References
- cisco-sa-asaftd-webvpn-z5xP8EUB sec.cloudapps.cisco.com · CVE Record https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurity...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CVE First | 2026-06-01 10:41 UTC |
| CISA | 2026-06-02 14:06 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Exploitation Status
Exploited in the wild
Recorded 2026-06-01 10:41:10 UTC · CVE
Weaknesses (CWE)
-
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
14:06 UTC about 2 months ago14:06 UTC · about 2 months ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
10:41 UTC about 2 months ago10:41 UTC · about 2 months ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
16:12 UTC 10 months ago16:12 UTC · 10 months ago
CVE published
Vulnerability disclosed publicly
-
19:15 UTC almost 2 years ago19:15 UTC · almost 2 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2025-20333
{
"cve_id": "CVE-2025-20333",
"title": "A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Secur...",
"affected_vendor": "Cisco",
"affected_product": "Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 9.9,
"epss_score": 0.40391,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}