CVE-2025-54309 in CrushFTP
Summary
by MITRE • 07/18/2025
CrushFTP 10 before 10.8.5 and 11 before 11.3.4_23, when the DMZ proxy feature is not used, mishandles AS2 validation and consequently allows remote attackers to obtain admin access via HTTPS, as exploited in the wild in July 2025.
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Analysis
by VulDB Data Team • 07/24/2025
The vulnerability identified as CVE-2025-54309 affects CrushFTP versions prior to 10.8.5 and 11.3.4_23, specifically when the DMZ proxy feature is not actively configured. This represents a critical authentication bypass flaw that directly compromises the security posture of affected systems. The vulnerability manifests through improper handling of AS2 validation processes, which are essential for secure communication protocols within the FTP framework. The flaw allows remote attackers to escalate privileges and gain administrative access to the system via HTTPS connections, making it particularly dangerous in production environments where such access could lead to complete system compromise.
The technical implementation of this vulnerability stems from insufficient validation mechanisms within the AS2 protocol handling layer of CrushFTP. When the DMZ proxy feature is disabled, the system fails to properly verify the authenticity and integrity of AS2 messages, creating a pathway for malicious actors to forge authentication requests. This weakness directly maps to CWE-287 which addresses improper authentication issues in software systems. The vulnerability is particularly concerning because it operates over HTTPS, which typically provides encryption and secure communication channels, yet the flawed validation process allows attackers to circumvent these security measures entirely.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to perform administrative functions within the compromised system. This includes but is not limited to user account management, file access modification, configuration changes, and potential lateral movement within network environments. The exploitation occurred in the wild during July 2025, indicating that threat actors were actively targeting these vulnerable systems. The fact that this vulnerability is exploitable without requiring special privileges or physical access makes it particularly dangerous for organizations that rely on CrushFTP for file transfer operations.
Security professionals should prioritize immediate patching of affected systems to address this vulnerability, as the attack vector is accessible over the network and requires no specialized tools or techniques. Organizations should also implement network monitoring to detect unusual authentication patterns or unauthorized access attempts that may indicate exploitation. The remediation process should include verification of the patch installation and confirmation that the DMZ proxy feature is properly configured if the system does not require its functionality. Additionally, organizations should conduct comprehensive security assessments to identify any potential compromise that may have occurred during the window of vulnerability. This vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and privilege escalation, as it allows unauthorized access through legitimate authentication mechanisms that have been improperly validated.