CVE-2012-10055 in FTP Server
Summary
by MITRE • 08/14/2025
ComSndFTP FTP Server version 1.3.7 Beta contains a format string vulnerability in its handling of the USER command. By sending a specially crafted username containing format specifiers, a remote attacker can overwrite a hardcoded function pointer in memory (specifically WSACleanup from Ws2_32.dll). This allows the attacker to redirect execution flow and bypass DEP protections using a ROP chain, ultimately leading to arbitrary code execution. The vulnerability is exploitable without authentication and affects default configurations.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/15/2025
The vulnerability identified as CVE-2012-10055 represents a critical format string vulnerability within ComSndFTP FTP Server version 1.3.7 Beta that fundamentally compromises the server's memory management integrity. This flaw exists specifically in the server's handling of the USER command, where the application fails to properly sanitize user input before processing it as a format string parameter. The vulnerability operates at a foundational level where the server's string formatting functions receive unvalidated input, creating an exploitable condition that allows attackers to manipulate memory layout directly.
The technical exploitation mechanism leverages the format string vulnerability to overwrite a hardcoded function pointer located in memory, specifically targeting WSACleanup from Ws2_32.dll. This particular function pointer serves as a critical execution control point within the server's operation, and its manipulation enables attackers to redirect program flow to arbitrary code locations. The vulnerability's exploitation does not require authentication, making it particularly dangerous as it can be triggered by any remote user connecting to the server. The attacker crafts a specially formatted username string containing format specifiers that, when processed by the vulnerable server, cause the program to write data to specific memory addresses controlled by the attacker.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a sophisticated pathway to bypass modern exploit mitigations including Data Execution Prevention (DEP). The exploitation technique employs Return-Oriented Programming (ROP) chains to circumvent DEP protections by chaining together existing code snippets within the application's memory space to achieve the desired malicious behavior. This approach allows the attacker to execute arbitrary code without injecting new code into memory, making detection more difficult and the attack more persistent. The vulnerability affects default configurations, meaning that any installation of ComSndFTP FTP Server version 1.3.7 Beta is immediately at risk without any additional configuration changes.
Security professionals should recognize this vulnerability as mapping to CWE-134, which specifically addresses format string vulnerabilities in applications that use untrusted data as format string parameters. The attack pattern aligns with techniques documented in the MITRE ATT&CK framework under the T1059.007 subtechnique for command and scripting interpreter, particularly when considering the execution of arbitrary code through memory manipulation. Organizations should immediately implement mitigations including patching to the latest version of the software, implementing network segmentation to restrict access to FTP services, and deploying intrusion detection systems that can identify the specific format string patterns associated with this exploit. The vulnerability demonstrates the critical importance of input validation and proper string handling in network services, as even a single unvalidated input parameter can provide complete system compromise.
The exploitation of this vulnerability highlights fundamental security weaknesses in legacy FTP server implementations that fail to properly validate user-supplied data. Modern security practices emphasize the principle of least privilege and input sanitization, where all user data should be treated as potentially malicious and validated before processing. The fact that this vulnerability can be exploited without authentication underscores the need for comprehensive network security controls including firewall rules, network access controls, and regular vulnerability assessments to identify and remediate similar issues in other network services. This particular vulnerability serves as a stark reminder of the importance of regular security updates and the dangers of running outdated software in production environments where it may be exposed to unauthenticated network access.