Common Weakness Enumeration

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CWE-234: Failure to Handle Missing Parameter

Weakness ID: 234
Vulnerability Mapping: DISCOURAGEDThis CWE ID should not be used to map to real-world vulnerabilities
Abstraction: VariantVariant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.
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+ Description
If too few arguments are sent to a function, the function will still pop the expected number of arguments from the stack. Potentially, a variable number of arguments could be exhausted in a function as well.
+ Relationships
Section HelpThis table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Research Concepts" (CWE-1000)
ChildOfBaseBase - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.233Improper Handling of Parameters
+ Modes Of Introduction
Section HelpThe different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.
+ Applicable Platforms
Section HelpThis listing shows possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.


Class: Not Language-Specific (Undetermined Prevalence)

+ Common Consequences
Section HelpThis table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Access Control

Technical Impact: Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity

There is the potential for arbitrary code execution with privileges of the vulnerable program if function parameter list is exhausted.

Technical Impact: DoS: Crash, Exit, or Restart

Potentially a program could fail if it needs more arguments then are available.
+ Likelihood Of Exploit
+ Demonstrative Examples

Example 1

The following example demonstrates the weakness.

(bad code)
Example Language:
foo_funct(one, two);

void foo_funct(int one, int two, int three) {
printf("1) %d\n2) %d\n3) %d\n", one, two, three);
(bad code)
Example Language:
void some_function(int foo, ...) {
int a[3], i;
va_list ap;
va_start(ap, foo);
for (i = 0; i < sizeof(a) / sizeof(int); i++) a[i] = va_arg(ap, int);

int main(int argc, char *argv[]) {
some_function(17, 42);

This can be exploited to disclose information with no work whatsoever. In fact, each time this function is run, it will print out the next 4 bytes on the stack after the two numbers sent to it.

+ Observed Examples
Server earlier allows remote attackers to cause a denial of service (crash) via an HTTP request with a sequence of "%" characters and a missing Host field.
Chat client allows remote malicious IRC servers to cause a denial of service (crash) via a PART message with (1) a missing channel or (2) a channel that the user is not in.
Proxy allows remote attackers to cause a denial of service (crash) via an HTTP request to helpout.exe with a missing HTTP version numbers.
Web server allows disclosure of CGI source code via an HTTP request without the version number.
Application server allows a remote attacker to read the source code to arbitrary 'jsp' files via a malformed URL request which does not end with an HTTP protocol specification.
Chat software allows remote attackers to cause a denial of service via malformed GIF89a headers that do not contain a GCT (Global Color Table) or an LCT (Local Color Table) after an Image Descriptor.
Server allows remote attackers to cause a denial of service (crash) via an HTTP GET request without a URI.
CGI crashes when called without any arguments.
CGI crashes when called without any arguments.
Crash in HTTP request without a Content-Length field.
Crash in HTTP request without a Content-Length field.
Empty elements/strings in protocol test suite affect many SSH2 servers/clients.
FTP server crashes in PORT command without an argument.
Resultant infoleak in web server via GET requests without HTTP/1.0 version string.
GET request with empty parameter leads to error message infoleak (path disclosure).
+ Potential Mitigations

Phase: Build and Compilation

This issue can be simply combated with the use of proper build process.

Phase: Implementation

Forward declare all functions. This is the recommended solution. Properly forward declaration of all used functions will result in a compiler error if too few arguments are sent to a function.
+ Memberships
Section HelpThis MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
MemberOfCategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.993SFP Secondary Cluster: Incorrect Input Handling
MemberOfCategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.1407Comprehensive Categorization: Improper Neutralization
+ Vulnerability Mapping Notes


(this CWE ID should not be used to map to real-world vulnerabilities)

Reasons: Potential Deprecation, Multiple Use


This CWE entry could be deprecated in a future version of CWE.


See maintenance notes.
+ Notes


This entry will be deprecated in a future version of CWE. The term "missing parameter" was used in both PLOVER and CLASP, with completely different meanings. However, data from both taxonomies was merged into this entry. In PLOVER, it was meant to cover malformed inputs that do not contain required parameters, such as a missing parameter in a CGI request. This entry's observed examples and classification came from PLOVER. However, the description, demonstrative example, and other information are derived from CLASP. They are related to an incorrect number of function arguments, which is already covered by CWE-685.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERMissing Parameter Error
CLASPMissing parameter
+ Content History
+ Submissions
Submission DateSubmitterOrganization
(CWE Draft 3, 2006-07-19)
+ Modifications
Modification DateModifierOrganization
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Common_Consequences, Relationships, Observed_Example, Other_Notes, Taxonomy_Mappings
2008-11-24CWE Content TeamMITRE
updated Observed_Examples
2009-03-09CWE Content TeamMITRE
added maintenance note: this entry will probably be deprecated
2009-03-10CWE Content TeamMITRE
updated Maintenance_Notes, Other_Notes, Potential_Mitigations
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Observed_Examples, Relationships
2013-07-17CWE Content TeamMITRE
updated Type
2014-07-30CWE Content TeamMITRE
updated Relationships
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Demonstrative_Examples
2020-02-24CWE Content TeamMITRE
updated Relationships
2023-04-27CWE Content TeamMITRE
updated Relationships, Time_of_Introduction
2023-06-29CWE Content TeamMITRE
updated Mapping_Notes
(CWE 4.14, 2024-02-29)
CWE Content TeamMITRE
updated Mapping_Notes
+ Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Missing Parameter Error
Page Last Updated: February 29, 2024