# CVE-2025-20333

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.

- Page: https://www.vulneraibility.com/cve/CVE-2025-20333
- CVSS: 9.9
- Known exploited: yes, in CISA KEV since 2025-09-25; CISA due date 2025-09-26
- EPSS: 71.21%
- Unvetted proof-of-concept code on GitHub: 3 GitHub proofs of concept (first 2026-05-16)
- CISA SSVC: exploitation active, automatable no, technical impact total (assessed 2025-09-26)
- Weakness: CWE-120
- Published: 2025-09-25

## Affected versions

- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: affected 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
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software: affected 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

A version outside these ranges is not a statement that it is unaffected.

## References

- [other] https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webvpn-z5xP8EUB
- [advisory] https://sec.cloudapps.cisco.com/security/center/resources/asa_ftd_continued_attacks
- [other] https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20333

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Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.