CVE-2025-20363CWE-122

CVE-2025-20363

Critical · published September 25, 2025

CVSS v3.1
9.0
EPSS
7%
Percentile
94.1
In the wild
Unconfirmed
What it is

🔥 A sneaky vulnerability in Cisco's Secure Firewall could let attackers execute arbitrary code remotely, and yes, you read that right – no authentication required! 😱 Think of this like a security guard at a high-end event who lets in anyone with a clever story, even if they don’t have proper credentials. An attacker can slip through, posing as a legitimate user to gain access and cause chaos! If exploited, this vulnerability could allow an attacker to take control of the affected device as root. This means they can manipulate, delete, or distribute data, turning your firewall from a protector into a tool for mischief! The ramifications could be absolutely devastating for your network's security.

Put simply

Think of this like a security guard at a high-end event who lets in anyone with a clever story, even if they don’t have proper credentials. An attacker can slip through, posing as a legitimate user to gain access and cause chaos! The vulnerability arises from improper validation of user-supplied input in HTTP requests on Cisco Secure Firewall ASA and FTD software, allowing unauthenticated attackers to craft requests that execute code on the device. Authenticated users with low privileges can also take advantage of this flaw in IOS, IOS XE, and IOS XR software.

What to do

If exploited, this vulnerability could allow an attacker to take control of the affected device as root. This means they can manipulate, delete, or distribute data, turning your firewall from a protector into a tool for mischief! The ramifications could be absolutely devastating for your network's security. Immediately update to the latest software versions provided by Cisco to patch this vulnerability. Ensure all HTTP requests are validated properly and consider implementing additional security measures such as intrusion detection systems to monitor suspicious activities. Don't wait - secure your systems now! You've got this! By taking swift action, you can transform from a potential victim into a security hero! 🦸‍♀️🦸‍♂️

The record
Technical detail
CVSS v3.1
9.0 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.06917 · 94.1th percentile
Weakness
CWE-122 · Heap-based Buffer Overflow
Published
2025-09-25T20:15Z
Affected products (28)
ProductVersionsFixed in
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/ios_xrall versions—
cisco/adaptive_security_appliance_software≥ 9.12, < 9.12.4.729.12.4.72
cisco/adaptive_security_appliance_software≥ 9.14, < 9.14.4.289.14.4.28
cisco/adaptive_security_appliance_software≥ 9.16, < 9.16.4.849.16.4.84
cisco/adaptive_security_appliance_software≥ 9.17.1, < 9.18.4.579.18.4.57
cisco/adaptive_security_appliance_software≥ 9.19.1, < 9.19.1.429.19.1.42
cisco/adaptive_security_appliance_software≥ 9.20.1, < 9.20.3.169.20.3.16
cisco/adaptive_security_appliance_software≥ 9.22, < 9.22.29.22.2
cisco/adaptive_security_appliance_software≥ 9.23, < 9.23.1.39.23.1.3
cisco/ios≥ 12.2\(15\)b, ≤ 15.9\(3\)m11—
cisco/ios_xe≥ 3.2.0sg, ≤ 17.17.1—
cisco/secure_firewall_threat_defense≥ 7.0.0, < 7.0.87.0.8
cisco/secure_firewall_threat_defense≥ 7.1.0, < 7.2.107.2.10
cisco/secure_firewall_threat_defense≥ 7.3.0, < 7.4.2.37.4.2.3
cisco/secure_firewall_threat_defense≥ 7.7.0, < 7.7.107.7.10
cisco/secure_firewall_threat_defenseall versions—
References (1)
EPSS history
Timeline
  • 25 SEP 16:12Z
    A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software…
    cvelistv5