The software does not release a file descriptor or handle after its effective lifetime has ended, i.e., after the file descriptor/handle is no longer needed. When a file descriptor or handle is not released after use (typically by explicitly closing it), attackers can cause a denial of service by consuming all available file descriptors/handles, or otherwise preventing other system processes from obtaining their own file descriptors/handles. 1000 Weakness ChildOf 772 699 Category ChildOf 769 888 Category ChildOf 892 Implementation Medium to High Availability DoS: resource consumption (other) When allocating resources without limits, an attacker could prevent all other processes from accessing the same type of resource. Operation Architecture and Design Limit Resource Consumption Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems. When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users. Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703). CVE-2007-0897 Chain: anti-virus product encounters a malformed file but returns from a function without closing a file descriptor (CWE-775) leading to file descriptor consumption (CWE-400) and failed scans. Vulnerability theory is largely about how behaviors and resources interact. "Resource exhaustion" can be regarded as either a consequence or an attack, depending on the perspective. This entry is an attempt to reflect one of the underlying weaknesses that enable these attacks (or consequences) to take place. Mark Dowd John McDonald Justin Schuh The Art of Software Security Assessment Chapter 10, "File Descriptor Leaks", Page 582. 1st Edition Addison Wesley 2006 2009-05-13 CWE Content Team MITRE 2009-12-28 updated Observed_Examples CWE Content Team MITRE 2010-04-05 updated Potential_Mitigations CWE Content Team MITRE 2011-06-01 updated Common_Consequences CWE Content Team MITRE 2012-05-11 updated References, Relationships CWE Content Team MITRE 2012-10-30 updated Potential_Mitigations