410
Phase: Implementation
Strategy = Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use
a list 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. This 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, denylists 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 allowlist validation schemes by
introducing dangerous inputs after they have been checked.
Observed Examples
Reference Description
CVE-2008-1284 NUL byte in theme name causes directory traversal impact to be worse
https://www.cve.org/CVERecord?id=CVE-2008-1284
CVE-2005-2008 Source code disclosure using trailing null.
https://www.cve.org/CVERecord?id=CVE-2005-2008
CVE-2005-3293 Source code disclosure using trailing null.
https://www.cve.org/CVERecord?id=CVE-2005-3293
CVE-2005-2061 Trailing null allows file include.
https://www.cve.org/CVERecord?id=CVE-2005-2061
CVE-2002-1774 Null character in MIME header allows detection bypass.
https://www.cve.org/CVERecord?id=CVE-2002-1774
CVE-2000-0149 Web server allows remote attackers to view the source code for CGI programs
via a null character (%00) at the end of a URL.
https://www.cve.org/CVERecord?id=CVE-2000-0149
CVE-2000-0671 Web server earlier allows allows remote attackers to bypass access
restrictions, list directory contents, and read source code by inserting a null
character (%00) in the URL.
https://www.cve.org/CVERecord?id=CVE-2000-0671
CVE-2001-0738 Logging system allows an attacker to cause a denial of service (hang) by
causing null bytes to be placed in log messages.
https://www.cve.org/CVERecord?id=CVE-2001-0738
CVE-2001-1140 Web server allows source code for executable programs to be read via a null
character (%00) at the end of a request.
https://www.cve.org/CVERecord?id=CVE-2001-1140
CVE-2002-1031 Protection mechanism for limiting file access can be bypassed using a null
character (%00) at the end of the directory name.
https://www.cve.org/CVERecord?id=CVE-2002-1031
CVE-2002-1025 Application server allows remote attackers to read JSP source code via an
encoded null byte in an HTTP GET request, which causes the server to send
the .JSP file unparsed.
https://www.cve.org/CVERecord?id=CVE-2002-1025
CWE Version 4.14
CWE-159: Improper Handling of Invalid Use of Special Elements
CWE-159: Improper Handling of Invalid Use of Special Elements