Type Vulnerability
Known ransomware campaign use: CVE-2025-20333 is listed in known-exploited catalogue (exploitation in the wild) CVE-2025-20362 has estimated attack likelihood 0.85543 (~85.5% estimated chance of…
Cisco · Memory corruption
Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability
CVE-2025-20333
What this means
This is rated critical severity (9.9 out of 10). It is on the known-exploited catalogue, which means attacks using it have already been seen. Ask IT whether Cisco Adaptive Security Appliance Software and Cisco Secure Firewall Threat Defense are in your estate, and treat that as the priority.
Full vendor description
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.
Scoring and exploitation
9.9/ 10
CVSS 3.1 base scoreCritical
Exploitable over the network with a low-privilege account, and no one has to click or open anything. High impact on confidentiality, integrity and availability, and it can reach beyond the vulnerable system.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Exploitability
Longer bar: easier to attack
Attack vectorNetworkAV:N
Attack complexityLowAC:L
Privileges requiredLowPR:L
User interactionNoneUI:N
ScopeChangedS:C
Impact
Longer bar: more harm
ConfidentialityHighC:H
IntegrityHighI:H
AvailabilityHighA:H
- Elevated attack likelihood (~72% in 30 days)Model estimate (): a probability signal, not confirmed exploitation
- Exploited in the wild
- Yes — confirmed exploitation (US CISA )
- Not reported
- Listed product
- Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense
Weaknesses
CWE-120
Affected products ()
- Cisco Adaptive Security Appliance Software
- Cisco Secure Firewall Threat Defense
Show the raw CPE strings (3)
- cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:secure_firewall_threat_defense:7.6.0:*:*:*:*:*:*:*
References
3 links from the CVE record, grouped by site; the vendor's advisory comes first.
sec.cloudapps.cisco.com2 linksVendor advisory
- cisco-sa-asaftd-webvpn-z5xP8EUB (opens in a new tab)Vendor Advisory
- asa_ftd_continued_attacks (opens in a new tab)Vendor Advisory
cisa.gov1 link
- known-exploited-vulnerabilities-catalog (opens in a new tab)US Government Resource