CVE-2025-20333

Analyzed

Published: 25 Sept 2025, 16:15

Last modified:26 Sept 2025, 14:08

Vulnerability Summary

Overall Risk

High Risk

70/100

CVSS Score

9.9 CRITICAL

v3.1

EPSS Score

1.03% LOW

77%ile 0.00%

CISA KEV

Active

Ransomware

Known Use

Exploits

None found

Dark Web

Not detected

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.

Source Identifier: psirt@cisco.com

CVSS	Source	Severity	Exploitability	Impact	Vector
v4.0	n/a
v3.1	psirt@cisco.com	9.9 CRITICAL	3.1	6	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H...
v3.0	n/a
v2.0	n/a

1.03%

Current Score

0.00%

77%ile

Percentile Rank

+0.01%

Loading chart...

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') CWE-120

Description:The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

Vulnerability Name:Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability

Added to CISA Catalog:25 Sept 2025, 00:00

Action Due:26 Sept 2025, 00:00

Known Ransomware: Ransomware

Required Action:The KEV due date refers to the deadline by which FCEB agencies are expected to review and begin implementing the guidance outlined in Emergency Directive (ED) 25-03 (URL listed below in Notes). Agencies must follow the mitigation steps provided by CISA (URL listed below in Notes) and vendor’s instructions (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.

No dark web activity detected for this vulnerability.

No known public exploit code indexed (as of 26 Sept 2025, 14:08).

Exploitation status can change quickly once PoC code appears.