[Update] Multiple vulnerabilities in Cisco ASA and FTD (September 25, 2025)

unknownknown exploitedpublic exploitCVE-2025-20333 CVE-2025-20362

Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.

[Update on November 7, 2025] On November 5, 2025, Cisco updated its blog post originally published on September 25, 2025 (see Documentation section). The vendor states it is aware of a new attack affecting vulnerable ASA and FTD devices, causing a denial...

CSIRTS triage

vendor: Cisco product: ASA and FTD Denial of service

What: A new attack affecting vulnerable ASA and FTD devices has been reported, causing denial of service.
Who is affected: Users of Cisco ASA and FTD devices are affected.
Urgency: Remediation is important as the vulnerability is actively exploited.
Action: Follow Cisco's updated guidance for mitigation.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: CERT-FR Alertes de sécurité (FR · national-cert · site)
Severity: unknown
Published: 2025-09-25
Exploitation: Observed in the wild (CISA KEV)
Language: Machine-translated to English — verify against the original

Original advisory: https://www.cert.ssi.gouv.fr/alerte/CERTFR-2025-ALE-013/

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Exploitation confirmedCVE-2025-20333Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 99.3% of all EPSS-scored CVEs.
Exploitation confirmedCVE-2025-20362Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 99.7% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2025-20333	coverage & exploitation status	NVD · CVE.org
CVE-2025-20362	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

unknownexploitedContinued Evolution of Persistence Mechanism Against Cisco Secure Firewall Adaptive Security Appliance and Sec…cisco-psirt
criticalexploitedCVE-2025-20362: Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FT…cisa-kev
criticalexploitedCVE-2025-20333: Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FT…cisa-kev

Recent advisories for Cisco ASA and

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highexploitedAL26-018 - Vulnerability affecting Cisco ASA and Secure Firewall Threat Defense Software Remote Access SSL VPN…cccs · 2026-08-13
unknownexploitedNCSC-2026-0295 [1.00] [M/H] Vulnerability patched in Cisco Secure Firewall ASA and FTD softwarencsc-nl · 2026-08-12
highexploited[NEW] [high] Cisco ASA (Adaptive Security Appliance) and Secure Firewall Threat Defense: Vulnerability enables…cert-bund · 2026-08-12
highexploitedCVE-2026-20349: A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Securi…nvd · 2026-08-11
criticalexploitedCVE-2026-20349: Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FT…cisa-kev · 2026-08-11
criticalexploitedCVE-2025-20362: Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FT…cisa-kev · 2025-09-25

[Update] Multiple vulnerabilities in Cisco ASA and FTD (September 25, 2025)

CSIRTS triage

Details

Exploitation outlook

Referenced CVEs

Same CVEs, other sources

Recent advisories for Cisco ASA and

More from CERT-FR Alertes de sécurité