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IMMUNITYSEC

CVE-2025-20333

9.9
CRITICAL
CVSS 3.1
EPSS 70.7% · 99th pctCISA KEV · Exploited in the wild
2025-09-25•Updated 2026-02-26•KEV 2025-09-25
CISA Known Exploited Vulnerabilities

Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV
2025-09-25
Remediation due
2025-09-26

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.

CISA notes
CISA Mitigation Instructions: https://www.cisa.gov/news-events/directives/ed-25-03-identify-and-mitigate-potential-compromise-cisco-devices ; https://www.cisa.gov/news-events/directives/supplemental-direction-ed-25-03-core-dump-and-hunt-instructions ; https://www.cisa.gov/eviction-strategies-tool/create-from-template ; https://sec.cloudapps.cisco.com/security/center/resources/asa_ftd_continued_attacks ; https://sec.cloudapps.cisco.com/security/center/private/resources/asa_ftd_continued_attacks#Details ; https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webvpn-z5xP8EUB ; https://nvd.nist.gov/vuln/detail/CVE-2025-20333

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.

Severity

CVSS 3.1 · CNA9.9 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
SSVC · CISA-ADP
Exploitationactive
Automatableno
Technical impacttotal

Affected Products

VendorProductAffected versions
CiscoCisco Secure Firewall Adaptive Security Appliance (ASA) Software
9.8.1
9.8.1.5
9.8.1.7
9.8.2
9.8.2.8
9.8.2.14
9.8.2.15
9.8.2.17
9.8.2.20
9.8.2.24
9.8.2.26
9.8.2.28
9.8.2.33
9.8.2.35
9.8.2.38
9.8.3.8
9.8.3.11
9.8.3.14
9.8.3.16
9.8.3.18
9.8.3.21
9.8.3
9.8.3.26
9.8.3.29
9.8.4
9.8.4.3
9.8.4.7
9.8.4.8
9.8.4.10
9.8.4.12
9.8.4.15
9.8.4.17
9.8.2.45
9.8.4.25
9.8.4.20
9.8.4.22
9.8.4.26
9.8.4.29
9.8.4.32
9.8.4.33
9.8.4.34
9.8.4.35
9.8.4.39
9.8.4.40
9.8.4.41
9.8.4.43
9.8.4.44
9.8.4.45
9.8.4.46
9.8.4.48
9.12.1
9.12.1.2
9.12.1.3
9.12.2
9.12.2.4
9.12.2.5
9.12.2.9
9.12.3
9.12.3.2
9.12.3.7
9.12.4
9.12.3.12
9.12.3.9
9.12.2.1
9.12.4.2
9.12.4.4
9.12.4.7
9.12.4.10
9.12.4.13
9.12.4.8
9.12.4.18
9.12.4.24
9.12.4.26
9.12.4.29
9.12.4.30
9.12.4.35
9.12.4.37
9.12.4.38
9.12.4.39
9.12.4.40
9.12.4.41
9.12.4.47
9.12.4.48
9.12.4.50
9.12.4.52
9.12.4.54
9.12.4.55
9.12.4.56
9.12.4.58
9.12.4.62
9.12.4.65
9.12.4.67
9.14.1
9.14.1.10
9.14.1.6
9.14.1.15
9.14.1.19
9.14.1.30
9.14.2
9.14.2.4
9.14.2.8
9.14.2.13
9.14.2.15
9.14.3
9.14.3.1
9.14.3.9
9.14.3.11
9.14.3.13
9.14.3.18
9.14.3.15
9.14.4
9.14.4.6
9.14.4.7
9.14.4.12
9.14.4.13
9.14.4.14
9.14.4.15
9.14.4.17
9.14.4.22
9.14.4.23
9.14.4.24
9.16.1
9.16.1.28
9.16.2
9.16.2.3
9.16.2.7
9.16.2.11
9.16.2.13
9.16.2.14
9.16.3
9.16.3.3
9.16.3.14
9.16.3.15
9.16.3.19
9.16.3.23
9.16.4
9.16.4.9
9.16.4.14
9.16.4.18
9.16.4.19
9.16.4.27
9.16.4.38
9.16.4.39
9.16.4.42
9.16.4.48
9.16.4.55
9.16.4.57
9.16.4.61
9.16.4.62
9.16.4.67
9.16.4.70
9.16.4.71
9.16.4.76
9.16.4.82
9.16.4.84
9.17.1
9.17.1.7
9.17.1.9
9.17.1.10
9.17.1.11
9.17.1.13
9.17.1.15
9.17.1.20
9.17.1.30
9.17.1.33
9.17.1.39
9.18.1
9.18.1.3
9.18.2
9.18.2.5
9.18.2.7
9.18.2.8
9.18.3
9.18.3.39
9.18.3.46
9.18.3.53
9.18.3.55
9.18.3.56
9.18.4
9.18.4.5
9.18.4.8
9.18.4.22
9.18.4.24
9.18.4.29
9.18.4.34
9.18.4.40
9.19.1
9.19.1.5
9.19.1.9
9.19.1.12
9.19.1.18
9.19.1.22
9.19.1.24
9.19.1.27
9.19.1.28
9.19.1.31
9.20.1
9.20.1.5
9.20.2
9.20.2.10
9.20.2.21
9.20.2.22
9.20.3
9.20.3.4
9.22.1.1
9.22.1.2
CiscoCisco Secure Firewall Threat Defense (FTD) Software
6.2.3
6.2.3.1
6.2.3.2
6.2.3.3
6.2.3.4
6.2.3.5
6.2.3.6
6.2.3.7
6.2.3.8
6.2.3.10
6.2.3.11
6.2.3.9
6.2.3.12
6.2.3.13
6.2.3.14
6.2.3.15
6.2.3.16
6.2.3.17
6.2.3.18
6.6.0
6.6.0.1
6.6.1
6.6.3
6.6.4
6.6.5
6.6.5.1
6.6.5.2
6.6.7
6.6.7.1
6.6.7.2
6.4.0
6.4.0.1
6.4.0.3
6.4.0.2
6.4.0.4
6.4.0.5
6.4.0.6
6.4.0.7
6.4.0.8
6.4.0.9
6.4.0.10
6.4.0.11
6.4.0.12
6.4.0.13
6.4.0.14
6.4.0.15
6.4.0.16
6.4.0.17
6.4.0.18
7.0.0
7.0.0.1
7.0.1
7.0.1.1
7.0.2
7.0.2.1
7.0.3
7.0.4
7.0.5
7.0.6
7.0.6.1
7.0.6.2
7.0.6.3
7.0.7
7.0.8
7.1.0
7.1.0.1
7.1.0.2
7.1.0.3
7.2.0
7.2.0.1
7.2.1
7.2.2
7.2.3
7.2.4
7.2.4.1
7.2.5
7.2.5.1
7.2.6
7.2.7
7.2.5.2
7.2.8
7.2.8.1
7.3.0
7.3.1
7.3.1.1
7.3.1.2
7.4.0
7.4.1
7.4.1.1
7.4.2
7.4.2.1
7.4.2.2
7.4.2.3
7.6.0

References

1 Links

Record Details

Published
2025-09-25
Last updated
2026-02-26
Assigner (CNA)
cisco
Credited to
-

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