CVE-2007-3770 in Xfce Terminal
Summary
by MITRE
The terminal_helper_execute function in terminal/terminal.c in Xfce Terminal 0.2.6 allows user-assisted remote attackers to execute arbitrary commands via shell metacharacters in a crafted link, as demonstrated using the "Open Link" functionality.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/21/2021
The vulnerability identified as CVE-2007-3770 represents a critical command injection flaw within the Xfce Terminal 0.2.6 software package. This issue resides in the terminal_helper_execute function located within the terminal/terminal.c source file, where the application fails to properly sanitize user-supplied input before processing it as part of command execution. The vulnerability specifically manifests when users interact with crafted links through the "Open Link" functionality, creating a user-assisted remote attack vector that can be exploited by malicious actors to execute arbitrary commands on affected systems. The flaw stems from inadequate input validation and sanitization mechanisms that allow shell metacharacters to be interpreted and executed by the underlying shell process, effectively bypassing normal security boundaries.
The technical implementation of this vulnerability demonstrates a classic command injection attack pattern where user-controllable data flows directly into shell execution contexts without proper escaping or encoding. When a user clicks on a maliciously crafted link containing shell metacharacters such as semicolons, ampersands, or backticks, the terminal application processes these characters as part of the command rather than as literal text. This behavior aligns with CWE-77, which describes improper neutralization of special elements used in commands, and represents a fundamental failure in input validation and output encoding. The vulnerability operates at the application layer and leverages the trust relationship between the user interface and the underlying shell execution environment, making it particularly dangerous in scenarios where users might encounter untrusted links in web pages, email messages, or other potentially malicious sources.
The operational impact of this vulnerability extends beyond simple command execution, as it can enable attackers to gain unauthorized access to system resources, escalate privileges, and potentially compromise the entire terminal session. An attacker could craft links that execute system commands such as file manipulation, network connectivity establishment, or even payload delivery mechanisms that could lead to full system compromise. The user-assisted nature of this vulnerability means that social engineering plays a crucial role in exploitation, requiring users to actively interact with malicious links, but once triggered, the consequences can be severe. This vulnerability directly impacts the integrity and confidentiality of terminal sessions, as demonstrated by ATT&CK technique T1059.001 for command and scripting interpreter execution, and represents a significant risk to desktop environments where users frequently interact with web content and external links.
Mitigation strategies for CVE-2007-3770 should focus on implementing proper input sanitization and escaping mechanisms within the terminal application's link handling functionality. The most effective approach involves ensuring that all user-supplied data passed to shell execution contexts undergoes comprehensive validation and encoding to prevent interpretation of shell metacharacters. System administrators should prioritize updating to patched versions of Xfce Terminal where the vulnerability has been addressed through proper input validation. Additionally, implementing network-level controls such as web application firewalls and link sanitization filters can provide additional defense-in-depth measures. Organizations should also consider implementing user education programs to raise awareness about the risks of clicking untrusted links and the importance of verifying source authenticity before interaction. The vulnerability highlights the importance of secure coding practices, particularly in applications that interface with system-level execution contexts, and serves as a reminder of the critical need for input validation at every layer of application processing.