CVEdetails.com the ultimate security vulnerability data source
(e.g.: CVE-2009-1234 or 2010-1234 or 20101234)
Log In   Register   Reset Password   Activate Account
Vulnerability Feeds & WidgetsNew   www.itsecdb.com  

CWE - 135 : Incorrect Calculation of Multi-Byte String Length

CWE Definition http://cwe.mitre.org/data/definitions/135.html
Number of vulnerabilities: 0
Description The software does not correctly calculate the length of strings that can contain wide or multi-byte characters.
Background Details
Other Notes There are several ways in which improper string length checking may result in an exploitable condition. All of these, however, involve the introduction of buffer overflow conditions in order to reach an exploitable state. The first of these issues takes place when the output of a wide or multi-byte character string, string-length function is used as a size for the allocation of memory. While this will result in an output of the number of characters in the string, note that the characters are most likely not a single byte, as they are with standard character strings. So, using the size returned as the size sent to new or malloc and copying the string to this newly allocated memory will result in a buffer overflow. Another common way these strings are misused involves the mixing of standard string and wide or multi-byte string functions on a single string. Invariably, this mismatched information will result in the creation of a possibly exploitable buffer overflow condition. Again, if a language subject to these flaws must be used, the most effective mitigation technique is to pay careful attention to the code at implementation time and ensure that these flaws do not occur.

Warning! CWE definitions are provided as a quick reference. They are not complete and may not be up to date!
You must visit http://cwe.mitre.org/ for a complete list of CWE entries and for more details.
CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site. OVAL is a registered trademark of The MITRE Corporation and the authoritative source of OVAL content is MITRE's OVAL web site.
Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.