CWE

Common Weakness Enumeration

A Community-Developed List of Software Weakness Types

CWE/SANS Top 25 Most Dangerous Software Errors
Home > CWE List > CWE- Individual Dictionary Definition (3.0)  
ID

CWE-698: Execution After Redirect (EAR)

Weakness ID: 698
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The web application sends a redirect to another location, but instead of exiting, it executes additional code.
+ Alternate Terms
Redirect Without Exit
+ Relationships

The table(s) below 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)
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
MemberOfCategoryCategory3617PK - Time and State
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Implementation
+ Common Consequences

The table below 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.

ScopeImpactLikelihood
Other
Confidentiality
Integrity
Availability

Technical Impact: Alter Execution Logic; Execute Unauthorized Code or Commands

This weakness could affect the control flow of the application and allow execution of untrusted code.
+ Demonstrative Examples

Example 1

This code queries a server and displays its status when a request comes from an authorized IP address.

(bad code)
Example Language: PHP 
$requestingIP = $_SERVER['REMOTE_ADDR'];
if(!in_array($requestingIP,$ipWhitelist)){
echo "You are not authorized to view this page";
http_redirect($errorPageURL);

}
$status = getServerStatus();
echo $status;
...

This code redirects unauthorized users, but continues to execute code after calling http_redirect(). This means even unauthorized users may be able to access the contents of the page or perform a DoS attack on the server being queried. Also, note that this code is vulnerable to an IP address spoofing attack (CWE-212).

+ Observed Examples
ReferenceDescription
Execution-after-redirect allows access to application configuration details.
chain: library file sends a redirect if it is directly requested but continues to execute, allowing remote file inclusion and path traversal.
Remote attackers can obtain access to administrator functionality through EAR.
Remote attackers can obtain access to administrator functionality through EAR.
Bypass of authentication step through EAR.
Chain: Execution after redirect triggers eval injection.
chain: execution after redirect allows non-administrator to perform static code injection.
+ Weakness Ordinalities
OrdinalityDescription
Primary
(where the weakness exists independent of other weaknesses)
+ Detection Methods

Black Box

This issue might not be detected if testing is performed using a web browser, because the browser might obey the redirect and move the user to a different page before the application has produced outputs that indicate something is amiss.
+ Memberships
This 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.
NatureTypeIDName
MemberOfViewView884CWE Cross-section
MemberOfCategoryCategory977SFP Secondary Cluster: Design
+ References
[REF-565] Adam Doupé, Bryce Boe, Christopher Kruegel and Giovanni Vigna. "Fear the EAR: Discovering and Mitigating Execution After Redirect Vulnerabilities". <http://cs.ucsb.edu/~bboe/public/pubs/fear-the-ear-ccs2011.pdf>.
+ Content History
Submissions
Submission DateSubmitterOrganization
2008-09-09CWE Content TeamMITRE
Modifications
Modification DateModifierOrganization
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Common_Consequences, Demonstrative_Examples, Relationships
2012-10-30CWE Content TeamMITRE
updated Demonstrative_Examples
2013-02-21CWE Content TeamMITRE
updated Alternate_Terms, Name, Observed_Examples, References
2014-07-30CWE Content TeamMITRE
updated Relationships
Previous Entry Names
Change DatePrevious Entry Name
2013-02-21Redirect Without Exit

More information is available — Please select a different filter.
Page Last Updated: January 18, 2018