Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Missing Authorization Vulnerability
Exploited since 2025-09-25. 2 of 8 rule sources name it; Cloudflare blocks by default. Our CRS test: blocked.
Update: On November 5, 2025, Cisco became aware of a new attack variant against devices running Cisco Secure ASA Software or Cisco Secure FTD Software releases that are affected by CVE-2025-20333 and CVE-2025-20362. This attack can cause… More
Update: On November 5, 2025, Cisco became aware of a new attack variant against devices running Cisco Secure ASA Software or Cisco Secure FTD Software releases that are affected by CVE-2025-20333 and CVE-2025-20362. This attack can cause unpatched devices to unexpectedly reload, leading to denial of service (DoS) conditions. Cisco strongly recommends that all customers upgrade to the fixed software releases that are listed in the Fixed Software ["#fs"] section of this advisory. 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 unauthenticated, remote attacker to access restricted URL endpoints that are related to remote access VPN that should otherwise be inaccessible without authentication. This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on a device. A successful exploit could allow the attacker to access a restricted URL without authentication.
Edge coverage
Claimed by vendorsAsk Vigil
AI · answers from this pageWorkers AI (Llama 3.3). Can be wrong: check the cited source.
Severity, decoded
CVSS 3.1Exploitable over the network, with no privileges and no user interaction, leading to low impact on confidentiality and integrity.
How the score is built
- Attack vectorAn attacker can reach it over the internet; no access to your network needed.Network
- Attack complexityNo special conditions are needed; the attack works reliably.Low
- Privileges requiredNo account or login is needed.None
- User interactionNo one has to click or open anything; the attack works on its own.None
- ScopeThe damage stays within the vulnerable component.Unchanged
- Confidentiality impactAn attacker can read some data, but has no control over what they get.Low
- Integrity impactAn attacker can change some data, but with limited control or limited effect.Low
- Availability impactThe component keeps working normally.None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NAttackers are exploiting this in the wild.
Attackers can script the attack end to end and hit many targets at once.
A successful attack gives limited control over the affected software or limited access to its data.
Public exploits
1 found- NucleiCVE-2025-20362.yamldetection template, replayed in our lab
Links are to third-party code: never run it outside an isolated lab.
Timeline
- 2025-09-25CVE publishedCVE List
- 2025-09-25Added to CISA KEVConfirmed exploitation in the wild
- 2025-09-28Cloudflare ships a ruleCisco Secure Firewall Adaptive Security Appliance - Remote Code Execution - CVE:CVE-2025-20333, CVE:CVE-2025-20362, CVE:CVE-2025-20363
- 2025-12-03F5 rule names itEarliest entry we can see is an update
- 2026-11-02Our test: OWASP Core Rule Set blocked itparanoia level 1, anomaly threshold 5, default CRS settings
- 2026-11-02Our test: OWASP Core Rule Set blocked itparanoia level 2, anomaly threshold 5, default CRS settings
Vendor statements
QuotedCloudflareWAF Managed Rules
First rule 2025-09-28, 3 days after the CVE was published.
Cisco Secure Firewall Adaptive Security Appliance - Remote Code Execution - CVE:CVE-2025-20333, CVE:CVE-2025-20362, CVE:CVE-2025-20363. Previous action: N/A. New action: Disabled. This is a New Detection
Cisco Secure Firewall Adaptive Security Appliance - Remote Code Execution - CVE:CVE-2025-20333, CVE:CVE-2025-20362, CVE:CVE-2025-20363. Previous action: N/A. New action: Disabled. This is a New Detection
Cisco Secure Firewall Adaptive Security Appliance - Remote Code Execution - CVE:CVE-2025-20333, CVE:CVE-2025-20362, CVE:CVE-2025-20363. Previous action: N/A. New action: Block. This is a New Detection
AWSAWS WAF Managed Rules
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. AWS often describes a vulnerability without naming its CVE (for example "Log4j"). We count only entries that name the CVE, so AWS coverage is understated.
Microsoft AzureFront Door and Application Gateway WAF (DRS)
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. The rule tables name CVEs but carry no dates, so Azure is left out of every time-to-rule figure.
Google CloudCloud Armor preconfigured WAF rules
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. Google names few CVEs: the release notes start in May 2024 and the rules reference lists CVEs without dates. Its cve-canary rules are opt-in.
FastlyNext-Gen WAF virtual patches
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
F5Attack signatures (Distributed Cloud WAF)
Named by 2025-12-03; the first entry is an update, so the rule may be older.
Updated: signature 200013049 "Cisco ASA authorization bypass" (Authentication/Authorization Attacks, risk High), systems: Cisco. References: CVE-2025-20362, CVE-2018-0296.
AkamaiApp & API Protector (Adaptive Security Engine)
This vendor publishes no machine-readable rule changelog we can check.
OWASP CRSCore Rule Set (open source, used inside many WAFs)
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. CRS rarely names CVEs: it relies on generic detections. Our own lab measures what it actually blocks.
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