High severity · published Aug 14, 2025
CVE-2025-20263
Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Buffer Overflow Denial of Service Vulnerability
8.6
CVSS
0.7%
EPSS
No
On KEV
Description
A vulnerability in the web services interface of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected system.
This vulnerability is due to insufficient boundary checks for specific data that is provided to the web services interface of an affected system. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected system. A successful exploit could allow the attacker to cause a buffer overflow condition on the affected system, which could cause the system to reload, resulting in a denial of service (DoS) condition.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 52% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CA
Cisco Adaptive Security Appliance (ASA) Software · Cisco
9.12.3; 9.8.3; 9.12.1; 9.8.1; 9.12.2; 9.8.2.45; +34 more · source: vendor
CF
Cisco Firepower Threat Defense Software · Cisco
6.2.3.14; 6.4.0.1; 6.2.3.7; 6.2.3; 6.4.0.2; 6.2.3.9; +34 more · source: vendor
Affected product
CA
Cisco Adaptive Security Appliance (ASA) Software
Cisco
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-20263
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-20263
sec.cloudapps.cisco.com
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-buffer-overflow-PyRUhWBC
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