CVE-2007-2348 in lftp
Summary
by MITRE
mirror --script in lftp before 3.5.9 does not properly quote shell metacharacters, which might allow remote user-assisted attackers to execute shell commands via a malicious script. NOTE: it is not clear whether this issue crosses security boundaries, since the script already supports commands such as "get" which could overwrite executable files.
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Analysis
by VulDB Data Team • 06/08/2025
The vulnerability identified as CVE-2007-2348 resides within the lftp file transfer client software, specifically affecting versions prior to 3.5.9. This security flaw manifests in the mirror --script functionality where the application fails to properly sanitize shell metacharacters during script execution. The issue creates a potential command injection vector that could be exploited by remote attackers who have the ability to influence script content. The vulnerability is classified as user-assisted, meaning that successful exploitation requires some form of user interaction or manipulation of the script content by an attacker. The lftp tool is commonly used for transferring files over various protocols including ftp, sftp, and http, making it a widely deployed utility in network administration and automation tasks.
The technical flaw stems from improper input validation and shell command construction within the mirror --script implementation. When lftp processes scripts containing shell commands, it does not adequately escape or quote special shell characters such as semicolons, ampersands, pipes, or backticks that could be interpreted by the underlying shell as command separators or operators. This lack of proper shell metacharacter escaping creates a condition where attacker-controlled input can be interpreted as additional shell commands rather than literal script content. The vulnerability is particularly concerning because it operates at the shell execution level, where malicious commands could potentially execute with the privileges of the user running lftp, or even with elevated privileges if the tool is run in a privileged context. This represents a classic command injection vulnerability that falls under the CWE-78 category of Improper Neutralization of Special Elements used in an OS Command.
The operational impact of this vulnerability extends beyond simple command execution, as it could enable attackers to compromise the integrity and confidentiality of systems using lftp for file transfers. An attacker who can influence a script file or manipulate the content of a script being processed by lftp could potentially overwrite executable files, execute arbitrary code, or even establish persistent access to the system. The fact that lftp scripts already support commands like "get" which can overwrite executable files creates a particularly dangerous scenario where an attacker could not only execute commands but also modify the tool itself or system binaries. This vulnerability could be leveraged in scenarios involving automated file transfers, where scripts are downloaded from untrusted sources or where users are tricked into executing malicious scripts. The potential for privilege escalation increases significantly if lftp is run with elevated permissions or if the affected system has other security weaknesses that could be exploited in conjunction with this vulnerability.
Mitigation strategies for CVE-2007-2348 should focus on immediate software updates to versions 3.5.9 or later where the shell metacharacter quoting issue has been addressed. System administrators should implement strict input validation and sanitization for any scripts that are processed by lftp, particularly those that originate from untrusted sources or are automatically downloaded from remote locations. The principle of least privilege should be enforced when running lftp, ensuring that the tool operates with minimal required permissions to reduce the potential impact of successful exploitation. Additionally, network segmentation and access controls should be implemented to limit the ability of remote attackers to influence script content or access systems running lftp. Organizations should also consider implementing monitoring and logging of lftp usage to detect anomalous script execution patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper input sanitization and shell escaping in applications that execute shell commands, aligning with ATT&CK techniques related to command and scripting interpreter execution and privilege escalation. Security awareness training for administrators should emphasize the risks associated with executing scripts from untrusted sources and the importance of validating script content before processing.