CWE-789 (未经控制的内存分配) — Vulnerability Class 241

241 vulnerabilities classified as CWE-789 (未经控制的内存分配). AI Chinese analysis included.

CWE-789 represents a critical memory management weakness where software allocates resources based on unvalidated, excessively large size values provided by external inputs. This flaw typically arises when developers fail to enforce upper bounds on integer parameters before invoking allocation functions, allowing attackers to supply maliciously crafted values that trigger massive memory consumption. Exploitation often leads to denial-of-service conditions through system exhaustion or resource starvation, potentially destabilizing the entire host environment. To mitigate this risk, developers must implement rigorous input validation strategies that strictly check size parameters against predefined, safe thresholds before any allocation occurs. Additionally, utilizing language-specific bounds checking mechanisms and static analysis tools can help identify potential overflows early in the development lifecycle, ensuring that memory requests remain within acceptable operational limits and preventing arbitrary resource depletion.

MITRE CWE Description

The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.

Common Consequences (1)

Availability DoS: Resource Consumption (Memory)

Not controlling memory allocation can result in a request for too much system memory, possibly leading to a crash of the application due to out-of-memory conditions, or the consumption of a large amount of memory on the system.

Mitigations (2)

Implementation, Architecture and Design Perform adequate input validation against any value that influences the amount of memory that is allocated. Define an appropriate strategy for handling requests that exceed the limit, and consider supporting a configuration option so that the administrator can extend the amount of memory to be used if necessary.

Operation Run your program using system-provided resource limits for memory. This might still cause the program to crash or exit, but the impact to the rest of the system will be minimized.

Examples (2)

Consider the following code, which accepts an untrusted size value and allocates a buffer to contain a string of the given size.

unsigned int size = GetUntrustedInt(); /* ignore integer overflow (CWE-190) for this example */ unsigned int totBytes = size * sizeof(char); char *string = (char *)malloc(totBytes); InitializeString(string);

Bad · C

Consider the following code, which accepts an untrusted size value and uses the size as an initial capacity for a HashMap.

unsigned int size = GetUntrustedInt(); HashMap list = new HashMap(size);

Bad · Java

CVE ID	Title	CVSS	Severity	Published
CVE-2017-7651	Eclipse Mosquitto 安全漏洞 — Eclipse Mosquitto	7.5	-	2018-04-24

Vulnerabilities classified as CWE-789 (未经控制的内存分配) represent 241 CVEs. The CWE taxonomy describes the weakness; review individual CVEs for product-specific impact.