The product uses a search path that contains an unquoted element, in which the element contains whitespace or other separators. This can cause the product to access resources in a parent path.
Extended Description
If a malicious individual has access to the file system, it is possible to elevate privileges by inserting such a file as "C:\Program.exe" to be run by a privileged program making use of WinExec.
Time of Introduction
Implementation
Applicable Platforms
Languages
All
Operating Systems
Windows 2000: (Sometimes)
Windows XP: (Sometimes)
Windows Vista: (Sometimes)
Mac OS X: (Rarely)
Platform Notes
This weakness could apply to any OS that supports spaces in filenames,
especially any OS that make it easy for a user to insert spaces into
filenames or folders, such as Windows. While spaces are technically
supported in Unix, the practice is generally avoided. .
Common Consequences
Scope
Effect
Confidentiality
Integrity
Availability
Technical Impact: Execute unauthorized code or
commands
Small handful of others. Program doesn't quote the
"C:\Program Files\" path when calling a program to be executed - or any
other path with a directory or file whose name contains a space - so
attacker can put a malicious program.exe into
C:.
Applies to "Common Files" folder, with a malicious
common.exe, instead of "Program
Files"/program.exe.
Potential Mitigations
Software should quote the input data that can be potentially executed
on a system.
Phase: Implementation
Strategy: Input Validation
Assume all input is malicious. Use an "accept known good" input
validation strategy, i.e., use a whitelist of acceptable inputs that
strictly conform to specifications. Reject any input that does not
strictly conform to specifications, or transform it into something that
does.
When performing input validation, consider all potentially relevant
properties, including length, type of input, the full range of
acceptable values, missing or extra inputs, syntax, consistency across
related fields, and conformance to business rules. As an example of
business rule logic, "boat" may be syntactically valid because it only
contains alphanumeric characters, but it is not valid if the input is
only expected to contain colors such as "red" or "blue."
Do not rely exclusively on looking for malicious or malformed inputs
(i.e., do not rely on a blacklist). A blacklist is likely to miss at
least one undesirable input, especially if the code's environment
changes. This can give attackers enough room to bypass the intended
validation. However, blacklists can be useful for detecting potential
attacks or determining which inputs are so malformed that they should be
rejected outright.
Phase: Implementation
Strategy: Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass whitelist validation schemes by introducing dangerous inputs after they have been checked.
This weakness primarily involves the lack of quoting, which is not explicitly stated as a part of CWE-116. CWE-116 also describes output in light of structured messages, but the generation of a filename or search path (as in this weakness) might not be considered a structured message.
An additional complication is the relationship to control spheres. Unlike untrusted search path (CWE-426), which inherently involves control over the definition of a control sphere, this entry concerns a fixed control sphere in which some part of the sphere may be under attacker control. This is not a clean fit under CWE-668 or CWE-610, which suggests that the control sphere model needs enhancement or clarification.
Description
