Opening temporary files without appropriate measures or controls can leave the file, its contents and any function that it impacts vulnerable to attack.
View on MITREIf the temporary file can be read by the attacker, sensitive information may be in that file which could be revealed.
If that file can be written to by the attacker, the file might be moved into a place to which the attacker does not have access. This will allow the attacker to gain selective resource access-control privileges.
Depending on the data stored in the temporary file, there is the potential for an attacker to gain an additional input vector which is trusted as non-malicious. It may be possible to make arbitrary changes to data structures, user information, or even process ownership.
Many contemporary languages have functions which properly handle this condition. Older C temp file functions are especially susceptible.
Ensure that you use proper file permissions. This can be achieved by using a safe temp file function. Temporary files should be writable and readable only by the process that owns the file.
Randomize temporary file names. This can also be achieved by using a safe temp-file function. This will ensure that temporary files will not be created in predictable places.
No detection method information available for this CWE.
In the following code examples a temporary file is created and written to. After using the temporary file, the file is closed and deleted from the file system.
However, within this C/C++ code the method tmpfile() is used to create and open the temp file. The tmpfile() method works the same way as the fopen() method would with read/write permission, allowing attackers to read potentially sensitive information contained in the temp file or modify the contents of the file.
In the following code examples a temporary file is created and written to. After using the temporary file, the file is closed and deleted from the file system.
However, within this C/C++ code the method tmpfile() is used to create and open the temp file. The tmpfile() method works the same way as the fopen() method would with read/write permission, allowing attackers to read potentially sensitive information contained in the temp file or modify the contents of the file.
A network application framework uses the Java function createTempFile(), which will create a file that is readable by other local users of the system
View DetailsCWE-378: Creation of Temporary File With Insecure Permissions is a Common Weakness Enumeration (CWE) entry maintained by MITRE. Opening temporary files without appropriate measures or controls can leave the file, its contents and any function that it impacts vulnerable to attack.
If exploited, CWE-378 (Creation of Temporary File With Insecure Permissions) it can compromise Confidentiality, Authorization, Other and Integrity, leading to outcomes such as Read Application Data and Other.
Recommended mitigations for CWE-378 include: Many contemporary languages have functions which properly handle this condition. Older C temp file functions are especially susceptible. Ensure that you use proper file permissions. This can be achieved by using a safe temp file function. Temporary files should be writable and readable only by the process that owns the file. Randomize temporary file names. This can also be achieved by using a safe temp-file function. This will ensure that temporary files will not be created in predictable places.
CWE-378 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
MITRE documents real CVEs mapped to CWE-378, including CVE-2022-24823. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.
A CWE (Common Weakness Enumeration) like CWE-378 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.