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CWE-616

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CWE-616

Incomplete Identification of Uploaded File Variables (PHP)

Variant
Incomplete

Description

The PHP application uses an old method for processing uploaded files by referencing the four global variables that are set for each file (e.g. $varname, $varname_size, $varname_name, $varname_type). These variables could be overwritten by attackers, causing the application to process unauthorized files.

These global variables could be overwritten by POST requests, cookies, or other methods of populating or overwriting these variables. This could be used to read or process arbitrary files by providing values such as "/etc/passwd".

Related Weaknesses

Common Consequences

Scope

Confidentiality
Integrity

Impact

Read Files or Directories, Modify Files or Directories

Potential Mitigations

Architecture and Design

Use PHP 4 or later.

Architecture and Design

If you must support older PHP versions, write your own version of is_uploaded_file() and run it against $HTTP_POST_FILES['userfile']))

Implementation

For later PHP versions, reference uploaded files using the $HTTP_POST_FILES or $_FILES variables, and use is_uploaded_file() or move_uploaded_file() to ensure that you are dealing with an uploaded file.

CVE-2002-1460

Forum does not properly verify whether a file was uploaded or if the associated variables were set by POST, allowing remote attackers to read arbitrary files.

CVE-2002-1759

Product doesn't check if the variables for an upload were set by uploading the file, or other methods such as $_POST.

CVE-2002-1710

Product does not distinguish uploaded file from other files.

Applicable Platforms

PHP

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