CVE-2013-10042 in freeFTPd
Summary
by MITRE • 07/31/2025
A stack-based buffer overflow vulnerability exists in freeFTPd version 1.0.10 and earlier in the handling of the FTP PASS command. When an attacker sends a specially crafted password string, the application fails to validate input length, resulting in memory corruption. This can lead to denial of service or arbitrary code execution. Exploitation requires the anonymous user account to be enabled.
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Analysis
by VulDB Data Team • 11/26/2025
The stack-based buffer overflow vulnerability identified as CVE-2013-10042 represents a critical security flaw in freeFTPd versions 1.0.10 and earlier, specifically within the handling of the FTP PASS command. This vulnerability falls under the Common Weakness Enumeration category CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations on the program stack. The flaw manifests when the application processes a specially crafted password string during the authentication phase of FTP connections, demonstrating a classic input validation failure that has been prevalent in network service applications for decades.
The technical implementation of this vulnerability exploits the fundamental weakness in how freeFTPd manages user authentication inputs, particularly focusing on the PASS command which is used to transmit user passwords to the FTP server. When an attacker submits an overly long password string, the application's insufficient input length validation causes the password data to overflow the allocated stack buffer, potentially overwriting critical program execution data including return addresses and function pointers. This memory corruption directly violates the principle of secure coding practices that mandate proper input validation and bounds checking before processing user-supplied data. The vulnerability's exploitation requires the anonymous user account to remain enabled, indicating that the flaw specifically impacts configurations where anonymous access is permitted, making it particularly concerning for publicly accessible FTP servers.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to encompass potential arbitrary code execution capabilities that could allow attackers to completely compromise affected systems. When successfully exploited, the buffer overflow can redirect program execution flow to attacker-controlled code, potentially enabling full system compromise or persistent backdoor access. The vulnerability's exploitation requires minimal privileges since it targets the authentication mechanism rather than requiring elevated system access, making it particularly dangerous for network services that are exposed to untrusted networks. This represents a significant concern for organizations running legacy FTP servers in production environments where the anonymous access feature remains enabled, as the vulnerability can be exploited remotely without requiring authentication.
Mitigation strategies for CVE-2013-10042 must address both immediate remediation and long-term architectural improvements in network service security. The most effective immediate solution involves upgrading to freeFTPd version 1.0.11 or later, which contains the necessary patches to prevent buffer overflow conditions in the PASS command handling. Organizations should also implement network segmentation and access controls to limit exposure of FTP services to trusted networks only, while disabling anonymous access where possible to eliminate the attack vector entirely. Additionally, security monitoring should be enhanced to detect unusual authentication patterns and potential exploitation attempts. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1190, which covers exploitation of vulnerabilities in network services, and demonstrates the importance of maintaining current software versions and implementing proper input validation mechanisms as outlined in security frameworks such as the OWASP Top Ten and NIST Cybersecurity Framework.