Missing Release of Resource after Effective Lifetime

Opis

The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.

Skutki

• Availability

  DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)

  An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.

Zapobieganie

• Requirements · Language Selection

  Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

  For example, languages such as Java, Ruby, and Lisp perform automatic garbage collection that releases memory for objects that have been deallocated.

• Implementation

  It is good practice to be responsible for freeing all resources you allocate and to be consistent with how and where you free resources in a function. If you allocate resources that you intend to free upon completion of the function, you must be sure to free the resources at all exit points for that function including error conditions.

• Operation, Architecture and Design · Resource Limitation

  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).

Przykłady podatności

• 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.
• CVE-2001-0830 Sockets not properly closed when attacker repeatedly connects and disconnects from server.
• CVE-1999-1127 Does not shut down named pipe connections if malformed data is sent.
• CVE-2009-2858 Chain: memory leak (CWE-404) leads to resource exhaustion.
• CVE-2009-2054 Product allows exhaustion of file descriptors when processing a large number of TCP packets.
• CVE-2008-2122 Port scan triggers CPU consumption with processes that attempt to read data from closed sockets.
• CVE-2007-4103 Product allows resource exhaustion via a large number of calls that do not complete a 3-way handshake.
• CVE-2002-1372 Chain: Return values of file/socket operations are not checked (CWE-252), allowing resultant consumption of file descriptors (CWE-772).

Słabość nadrzędna

• CWE-404 Improper Resource Shutdown or Release

Słabości podrzędne

• CWE-401 Missing Release of Memory after Effective Lifetime
• CWE-775 Missing Release of File Descriptor or Handle after Effective Lifetime
• CWE-1091 Use of Object without Invoking Destructor Method

Kiedy powstaje

• Implementation

Dotyczy

Mobile

Uwagi

"Resource exhaustion" (CWE-400) is currently treated as a weakness, although it is more like a category of weaknesses that all have the same type of consequence. While this entry treats CWE-400 as a parent in view 1000, the relationship is probably more appropriately described as a chain.

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.

Źródła

1. Automated Source Code Reliability Measure (ASCRM) — Object Management Group (OMG), ASCRM-CWE-772, 2016
2. Automated Source Code Security Measure (ASCSM) — Object Management Group (OMG), ASCSM-CWE-772, 2016