CVE-2025-20363 in IOS
Summary
by MITRE • 09/25/2025
A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software, Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, remote attacker (Cisco ASA and FTD Software) or authenticated, remote attacker (Cisco IOS, IOS XE, and IOS XR Software) with low user privileges to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web service on an affected device after obtaining additional information about the system, overcoming exploit mitigations, or both. A successful exploit could allow the attacker to execute arbitrary code as root, which may lead to the complete compromise of the affected device. For more information about this vulnerability, see the Details ["#details"] section of this advisory.
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Analysis
by VulDB Data Team • 02/10/2026
This vulnerability represents a critical remote code execution flaw affecting multiple Cisco networking products including ASA, FTD, IOS, IOS XE, and IOS XR software versions. The issue stems from inadequate input validation mechanisms within the web services component of these security appliances, creating a pathway for attackers to escalate privileges and gain full system control. The vulnerability's exploitation requires either unauthenticated access for ASA and FTD devices or authenticated access with low privileges for IOS family products, demonstrating the varying attack vectors across different software implementations.
The technical root cause of CVE-2025-20363 aligns with CWE-20, which describes improper input validation in software systems. This weakness allows malicious HTTP requests to bypass normal security checks and inject arbitrary code into the target device's memory space. Attackers must craft specific HTTP payloads that exploit the validation gaps in the web service interface, potentially requiring reconnaissance to understand the target system's configuration and version details. The exploitation process likely involves buffer overflow techniques or command injection methods that leverage the insufficient sanitization of user-supplied data.
The operational impact of this vulnerability is severe and potentially catastrophic for network security infrastructure. Successful exploitation results in complete device compromise with root-level privileges, enabling attackers to execute arbitrary code, modify system configurations, access sensitive data, and establish persistent backdoors. This vulnerability directly violates fundamental security principles by allowing privilege escalation from low-privilege users to full system administrator access. Organizations running affected Cisco products face significant risk of network infiltration, data breaches, and complete loss of security control over their network infrastructure.
Mitigation strategies should focus on immediate patch deployment for all affected software versions, as well as network segmentation and access control measures. Implementing web application firewalls, disabling unnecessary web services, and restricting HTTP access to trusted networks can provide temporary protection while patches are deployed. Security teams should also monitor for suspicious HTTP traffic patterns and implement intrusion detection systems to identify potential exploitation attempts. According to ATT&CK framework, this vulnerability maps to T1059 (Command and Scripting Interpreter) and T1068 (Exploitation for Privilege Escalation) techniques, making it particularly dangerous for adversaries seeking to establish persistent access to network infrastructure. Organizations should also consider implementing network access controls and privilege separation measures to limit the potential impact of successful exploitation attempts.