CWE-1325: Improperly Controlled Sequential Memory Allocation

Extended Description

While the product might limit the amount of memory that is allocated in a single operation for a single object (such as a malloc of an array), if an attacker can cause multiple objects to be allocated in separate operations, then this might cause higher total memory consumption than the developer intended, leading to a denial of service.

Code Examples & CVEs

Demonstrative Examples

This example contains a small allocation of stack memory. When the program was first constructed, the number of times this memory was allocated was probably inconsequential and presented no problem. Over time, as the number of objects in the database grow, the number of allocations will grow - eventually consuming the available stack, i.e. "stack exhaustion." An attacker who is able to add elements to the database could cause stack exhaustion more rapidly than assumed by the developer.

Since this uses alloca(), it allocates memory directly on the stack. If end_limit is large enough, then the stack can be entirely consumed.

BadC

// Gets the size from the number of objects in a database, which over time can conceivably get very large 					  int end_limit = get_nmbr_obj_from_db(); 					  int i; 					  int *base = NULL; 					  int *p =base; 					  for (i = 0; i < end_limit; i++) 					  { 					     					      *p = alloca(sizeof(int *)); // Allocate memory on the stack 					      p = *p; // // Point to the next location to be saved 					     					    }

Observed CVE Examples (3)

CVE-2020-36049

JavaScript-based packet decoder uses concatenation of many small strings, causing out-of-memory (OOM) condition

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CVE-2019-20176

Product allocates a new buffer on the stack for each file in a directory, allowing stack exhaustion

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CVE-2013-1591

Chain: an integer overflow (CWE-190) in the image size calculation causes an infinite loop (CWE-835) which sequentially allocates buffers without limits (CWE-1325) until the stack is full.

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Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-1325 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-1325, Improperly Controlled Sequential Memory Allocation, throughout the product lifecycle. Derive review questions, static or dynamic checks, and negative tests from the CWE's causal behavior; define the components and lifecycle stages each check covers; and retain findings with enough evidence to distinguish the root cause from symptoms and impacts. Track escapes and false negatives, then improve the verification plan after every confirmed occurrence.

NIST SP 800-218 Secure Software Development Framework — National Institute of Standards and Technology

Address Improperly Controlled Sequential Memory Allocation during Implementation

MITRE associates mitigation with Implementation, and Operation; recorded impacts include DoS: Resource Consumption (Memory); the entry maps to CAPEC-130. Use these source-defined anchors to turn CWE-1325 into implementation, review, and verification checks for the affected component.

CWE-1325: Improperly Controlled Sequential Memory Allocation — MITRE CWE

Triage CWE-1325 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-1325, Improperly Controlled Sequential Memory Allocation, has evidence of exploitation in the wild. Confirm the CVE-to-CWE root-cause mapping independently before attaching the example, then capture the affected product, required action, and remediation deadline. A missing KEV match is not evidence that the weakness is unexploited, and a KEV entry must not be generalized to every occurrence of this CWE.

Known Exploited Vulnerabilities Catalog — Cybersecurity and Infrastructure Security Agency

Apply precise root-cause mapping to CWE-1325

Apply MITRE's full root-cause mapping guidance when using CWE-1325, Improperly Controlled Sequential Memory Allocation. Separate weakness language from attacker prerequisites and technical impact, check the entry's abstraction and vulnerability-mapping notes, and prefer the most specific Base or Variant supported by the evidence. Record the rejected alternatives and require an independent review before the mapping is used for remediation trends or program metrics.

CVE to CWE Root Cause Mapping Guidance — MITRE CWE

Validate CWE-1325 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-1325, Improperly Controlled Sequential Memory Allocation. Confirm the finding describes the causal weakness rather than an impact or attack pattern, compare the abstraction and mapping notes with plausible alternatives, and have a second reviewer challenge the selection. Preserve the evidence and reasoning so recurring defects can be measured against one consistent identifier.

CVE to CWE Root Cause Mapping Quick Tips — MITRE CWE

Frequently Asked Questions

What is CWE-1325: Improperly Controlled Sequential Memory Allocation?+

CWE-1325: Improperly Controlled Sequential Memory Allocation is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product manages a group of objects or resources and performs a separate memory allocation for each object, but it does not properly limit the total amount of memory that is consumed by all of the combined objects. While the product might limit the amount of memory that is allocated in a single operation for a single object (such as a malloc of an array), if an attacker can cause multiple objects to be allocated in separate operations, then this might cause higher total memory consumption than the developer intended, leading to a denial of service.

What are the security consequences of Improperly Controlled Sequential Memory Allocation?+

If exploited, CWE-1325 (Improperly Controlled Sequential Memory Allocation) it can compromise Availability, leading to outcomes such as DoS: Resource Consumption (Memory).

How do you prevent or mitigate Improperly Controlled Sequential Memory Allocation?+

Recommended mitigations for CWE-1325 include: Ensure multiple allocations of the same kind of object are properly tracked - possibly across multiple sessions, requests, or messages. 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. Run the 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.

Which programming languages are affected by Improperly Controlled Sequential Memory Allocation?+

CWE-1325 commonly affects C, C++ and Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

What are real-world examples of Improperly Controlled Sequential Memory Allocation?+

MITRE documents real CVEs mapped to CWE-1325, including CVE-2020-36049, CVE-2019-20176 and CVE-2013-1591. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.

What is the difference between a CWE and a CVE?+

A CWE (Common Weakness Enumeration) like CWE-1325 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.

CWE-1325: Improperly Controlled Sequential Memory Allocation

Extended Description

Technical Details

Applicable To

Security Consequences

Scope

Impact

Mitigation Strategies

Phase

Description

Phase

Description

Detection Methods

Code Examples & CVEs

Demonstrative Examples

Observed CVE Examples (3)

CWE Relationships

Parent Weaknesses

Source-backed guidance

Verify controls for CWE-1325 with SSDF evidence

Address Improperly Controlled Sequential Memory Allocation during Implementation

Triage CWE-1325 against known exploitation evidence

Apply precise root-cause mapping to CWE-1325

Validate CWE-1325 with root-cause mapping checks

Frequently Asked Questions

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