CWE-363: Race Condition Enabling Link Following
View customized information:
For users who are interested in more notional aspects of a weakness. Example: educators, technical writers, and project/program managers.
For users who are concerned with the practical application and details about the nature of a weakness and how to prevent it from happening. Example: tool developers, security researchers, pen-testers, incident response analysts.
For users who are mapping an issue to CWE/CAPEC IDs, i.e., finding the most appropriate CWE for a specific issue (e.g., a CVE record). Example: tool developers, security researchers.
For users who wish to see all available information for the CWE/CAPEC entry.
For users who want to customize what details are displayed.
×
Edit Custom FilterThe product checks the status of a file or directory before accessing it, which produces a race condition in which the file can be replaced with a link before the access is performed, causing the product to access the wrong file.
While developers might expect that there is a very narrow time window between the time of check and time of use, there is still a race condition. An attacker could cause the product to slow down (e.g. with memory consumption), causing the time window to become larger. Alternately, in some situations, the attacker could win the race by performing a large number of attacks.
This 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.
This 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)
The 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.
This 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.
Languages Class: Not Language-Specific (Undetermined Prevalence) Example 1 This code prints the contents of a file if a user has permission. (bad code)
Example Language: PHP
function readFile($filename){
$user = getCurrentUser();
//resolve file if its a symbolic link if(is_link($filename)){ $filename = readlink($filename); }if(fileowner($filename) == $user){ echo file_get_contents($realFile); }return; else{ echo 'Access denied'; }return false; This code attempts to resolve symbolic links before checking the file and printing its contents. However, an attacker may be able to change the file from a real file to a symbolic link between the calls to is_link() and file_get_contents(), allowing the reading of arbitrary files. Note that this code fails to log the attempted access (CWE-778).
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.
Relationship
This is already covered by the "Link Following" weakness (CWE-59). It is included here because so many people associate race conditions with link problems; however, not all link following issues involve race conditions.
More information is available — Please edit the custom filter or select a different filter. |
Use of the Common Weakness Enumeration (CWE™) and the associated references from this website are subject to the Terms of Use. CWE is sponsored by the U.S. Department of Homeland Security (DHS) Cybersecurity and Infrastructure Security Agency (CISA) and managed by the Homeland Security Systems Engineering and Development Institute (HSSEDI) which is operated by The MITRE Corporation (MITRE). Copyright © 2006–2024, The MITRE Corporation. CWE, CWSS, CWRAF, and the CWE logo are trademarks of The MITRE Corporation. |