CVE-2001-1375 in TCL TK
Summary
by MITRE
tcl/tk package (tcltk) 8.3.1 searches for its libraries in the current working directory before other directories, which could allow local users to execute arbitrary code via a Trojan horse library that is under a user-controlled directory.
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Analysis
by VulDB Data Team • 06/14/2024
The vulnerability identified as CVE-2001-1375 resides within the tcl/tk package version 8.3.1, specifically addressing a critical flaw in the library loading mechanism that fundamentally compromises system security through improper path resolution. This vulnerability represents a classic example of a library injection attack vector where the software's dynamic library loader prioritizes the current working directory over standard system paths, creating an exploitable condition that can be leveraged by malicious actors.
The technical flaw manifests in the library search order implementation where the tcl/tk interpreter performs a breadth-first search for required shared libraries, beginning with the current working directory before consulting system library paths such as /usr/lib or /lib. This design decision creates a race condition scenario where a local attacker can place a malicious library file with the same name as a legitimate system library in a directory under their control, causing the interpreter to load the malicious version instead of the intended system library. The vulnerability operates under the principle of path traversal and library injection, which is categorized under CWE-426 as an Untrusted Search Path and falls within the ATT&CK framework under T1059.007 for Command and Scripting Interpreter with potential privilege escalation implications.
The operational impact of this vulnerability extends beyond simple code execution, as it enables attackers to gain unauthorized access to systems through a relatively simple attack vector that requires minimal privileges. Local users can exploit this flaw by placing malicious shared libraries in directories they control, potentially leading to privilege escalation if the tcl/tk interpreter runs with elevated privileges or if the interpreter is used in applications that perform sensitive operations. The vulnerability is particularly concerning because it can be exploited in environments where users have write access to directories or where applications are run in user contexts that allow for such directory manipulation.
Mitigation strategies for CVE-2001-1375 require both immediate and long-term approaches to address the underlying library loading vulnerability. System administrators should immediately update to patched versions of the tcl/tk package where the library search order has been corrected to prioritize system directories over the current working directory. Additionally, implementing proper directory permissions and access controls can help prevent unauthorized library placement in user-controlled directories. The use of secure coding practices such as explicit library path specification and runtime library loading restrictions should be enforced, particularly for applications that dynamically load shared libraries. Organizations should also consider implementing application whitelisting solutions and monitoring for suspicious library loading patterns to detect potential exploitation attempts. This vulnerability underscores the importance of proper privilege separation and secure library loading mechanisms as outlined in security standards such as the OWASP Secure Coding Practices and NIST guidelines for secure software development.