The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product's direct control.
Hard-code the search path to a set of known-safe values (such as system directories), or only allow them to be specified by the administrator in a configuration file. Do not allow these settings to be modified by an external party. Be careful to avoid related weaknesses such as CWE-426 and CWE-428.
When invoking other programs, specify those programs using fully-qualified pathnames. While this is an effective approach, code that uses fully-qualified pathnames might not be portable to other systems that do not use the same pathnames. The portability can be improved by locating the full-qualified paths in a centralized, easily-modifiable location within the source code, and having the code refer to these paths.
Remove or restrict all environment settings before invoking other programs. This includes the PATH environment variable, LD_LIBRARY_PATH, and other settings that identify the location of code libraries, and any application-specific search paths.
Check your search path before use and remove any elements that are likely to be unsafe, such as the current working directory or a temporary files directory.
Use other functions that require explicit paths. Making use of any of the other readily available functions that require explicit paths is a safe way to avoid this problem. For example, system() in C does not require a full path since the shell can take care of it, while execl() and execv() require a full path.
There is the potential for arbitrary code execution with privileges of the vulnerable program.
The program could be redirected to the wrong files, potentially triggering a crash or hang when the targeted file is too large or does not have the expected format.
The program could send the output of unauthorized files to the attacker.
Use monitoring tools that examine the software's process as it interacts with the operating system and the network. This technique is useful in cases when source code is unavailable, if the software was not developed by you, or if you want to verify that the build phase did not introduce any new weaknesses. Examples include debuggers that directly attach to the running process; system-call tracing utilities such as truss (Solaris) and strace (Linux); system activity monitors such as FileMon, Reg...
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Use tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session. These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.
CVE-1999-1120Application relies on its PATH environment variable to find and execute program.
CVE-2008-1810Database application relies on its PATH environment variable to find and execute program.
CVE-2007-2027Chain: untrusted search path enabling resultant format string by loading malicious internationalization messages.
CVE-2008-3485Untrusted search path using malicious .EXE in Windows environment.
CVE-2008-2613setuid program allows compromise using path that finds and loads a malicious library.