CVE-2007-0908 - Improper Input Validation

Severity

50%

Complexity

99%

Confidentiality

48%

The WDDX deserializer in the wddx extension in PHP 5 before 5.2.1 and PHP 4 before 4.4.5 does not properly initialize the key_length variable for a numerical key, which allows context-dependent attackers to read stack memory via a wddxPacket element that contains a variable with a string name before a numerical variable.

The WDDX deserializer in the wddx extension in PHP 5 before 5.2.1 and PHP 4 before 4.4.5 does not properly initialize the key_length variable for a numerical key, which allows context-dependent attackers to read stack memory via a wddxPacket element that contains a variable with a string name before a numerical variable.

CVSS 2.0 Base Score 5. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (AV:N/AC:L/Au:N/C:P/I:N/A:N).

Demo Examples

Improper Input Validation

CWE-20

This example demonstrates a shopping interaction in which the user is free to specify the quantity of items to be purchased and a total is calculated.


               
...

The user has no control over the price variable, however the code does not prevent a negative value from being specified for quantity. If an attacker were to provide a negative value, then the user would have their account credited instead of debited.

Improper Input Validation

CWE-20

This example asks the user for a height and width of an m X n game board with a maximum dimension of 100 squares.


               
.../* board dimensions */
die("No integer passed: Die evil hacker!\n");
die("No integer passed: Die evil hacker!\n");
die("Value too large: Die evil hacker!\n");

While this code checks to make sure the user cannot specify large, positive integers and consume too much memory, it does not check for negative values supplied by the user. As a result, an attacker can perform a resource consumption (CWE-400) attack against this program by specifying two, large negative values that will not overflow, resulting in a very large memory allocation (CWE-789) and possibly a system crash. Alternatively, an attacker can provide very large negative values which will cause an integer overflow (CWE-190) and unexpected behavior will follow depending on how the values are treated in the remainder of the program.

Improper Input Validation

CWE-20

The following example shows a PHP application in which the programmer attempts to display a user's birthday and homepage.


               
echo "Birthday: $birthday<br>Homepage: <a href=$homepage>click here</a>"

The programmer intended for $birthday to be in a date format and $homepage to be a valid URL. However, since the values are derived from an HTTP request, if an attacker can trick a victim into clicking a crafted URL with <script> tags providing the values for birthday and / or homepage, then the script will run on the client's browser when the web server echoes the content. Notice that even if the programmer were to defend the $birthday variable by restricting input to integers and dashes, it would still be possible for an attacker to provide a string of the form:


               
2009-01-09--

If this data were used in a SQL statement, it would treat the remainder of the statement as a comment. The comment could disable other security-related logic in the statement. In this case, encoding combined with input validation would be a more useful protection mechanism.

Furthermore, an XSS (CWE-79) attack or SQL injection (CWE-89) are just a few of the potential consequences when input validation is not used. Depending on the context of the code, CRLF Injection (CWE-93), Argument Injection (CWE-88), or Command Injection (CWE-77) may also be possible.

Improper Input Validation

CWE-20

This function attempts to extract a pair of numbers from a user-supplied string.


               
}
die("Did not specify integer value. Die evil hacker!\n");
/* proceed assuming n and m are initialized correctly */

This code attempts to extract two integer values out of a formatted, user-supplied input. However, if an attacker were to provide an input of the form:


               
123:

then only the m variable will be initialized. Subsequent use of n may result in the use of an uninitialized variable (CWE-457).

Improper Input Validation

CWE-20

The following example takes a user-supplied value to allocate an array of objects and then operates on the array.


               
}
list[0] = new Widget();
die("Negative value supplied for list size, die evil hacker!");

This example attempts to build a list from a user-specified value, and even checks to ensure a non-negative value is supplied. If, however, a 0 value is provided, the code will build an array of size 0 and then try to store a new Widget in the first location, causing an exception to be thrown.

Improper Input Validation

CWE-20

This application has registered to handle a URL when sent an intent:


               
}......
}
}
int length = URL.length();
...

The application assumes the URL will always be included in the intent. When the URL is not present, the call to getStringExtra() will return null, thus causing a null pointer exception when length() is called.

Overview

First reported 18 years ago

2007-02-13 23:28:00

Last updated 6 years ago

2018-10-30 16:26:00

Affected Software

PHP 4.0.0

4.0

PHP PHP 4.0 Beta 1

4.0

PHP PHP 4.0 Beta 2

4.0

PHP PHP 4.0 Beta 3

4.0

PHP PHP 4.0 Beta 4

4.0

PHP PHP 4.0 Beta 4 Patch Level 1

4.0

PHP 4.0 Release Candidate 1

4.0

PHP 4.0 Release Candidate 2

4.0

PHP PHP

Canonical Ubuntu Linux 5.10

5.10

Canonical Ubuntu Linux 6.06 LTS (Long-Term Support)

6.06

Canonical Ubuntu Linux 6.10

6.10

References

20070201-01-P

Broken Link

SUSE-SA:2007:020

Broken Link

32766

Broken Link

RHSA-2007:0089

Third Party Advisory

24089

Third Party Advisory

24195

Third Party Advisory

24217

Third Party Advisory

24236

Third Party Advisory

24248

Third Party Advisory

24284

Third Party Advisory

24295

Third Party Advisory

24322

Third Party Advisory

24419

Third Party Advisory

24421

Third Party Advisory

24432

Third Party Advisory

24514

Third Party Advisory

24606

Third Party Advisory

24642

Third Party Advisory

GLSA-200703-21

Third Party Advisory

2321

Third Party Advisory

http://support.avaya.com/elmodocs2/security/ASA-2007-101.htm

Third Party Advisory

http://support.avaya.com/elmodocs2/security/ASA-2007-136.htm

Third Party Advisory

MDKSA-2007:048

Third Party Advisory

OpenPKG-SA-2007.010

Third Party Advisory

http://www.php.net/ChangeLog-5.php#5.2.1

Third Party Advisory

http://www.php.net/releases/5_2_1.php

Third Party Advisory

http://www.php-security.org/MOPB/MOPB-11-2007.html

Third Party Advisory

RHSA-2007:0076

Third Party Advisory

RHSA-2007:0081

Third Party Advisory

RHSA-2007:0082

Third Party Advisory

RHSA-2007:0088

Third Party Advisory

20070227 rPSA-2007-0043-1 php php-mysql php-pgsql

Third Party Advisory, VDB Entry

22496

Patch, Third Party Advisory, VDB Entry

22806

Third Party Advisory, VDB Entry

1017671

Third Party Advisory, VDB Entry

2007-0009

Broken Link

USN-424-1

Third Party Advisory

USN-424-2

Third Party Advisory

DSA-1264

Broken Link

ADV-2007-0546

Permissions Required, Third Party Advisory

php-wddx-information-disclosure(32493)

Third Party Advisory, VDB Entry

https://issues.rpath.com/browse/RPL-1088

Broken Link

oval:org.mitre.oval:def:11185

Third Party Advisory

Stay updated

ExploitPedia is constantly evolving. Sign up to receive a notification when we release additional functionality.

Get in touch

If you'd like to report a bug or have any suggestions for improvements then please do get in touch with us using this form. We will get back to you as soon as we can.