CWE-1246: Improper Write Handling in Limited-write Non-Volatile Memories

Extended Description

Non-volatile memories such as NAND Flash, EEPROM, etc. have individually erasable segments, each of which can be put through a limited number of program/erase or write cycles. For example, the device can only endure a limited number of writes, after which the device becomes unreliable. In order to wear out the cells in a uniform manner, non-volatile memory and storage products based on the above-mentioned technologies implement a technique called wear leveling. Once a set threshold is reached, wear leveling maps writes of a logical block to a different physical block. This prevents a single physical block from prematurely failing due to a high concentration of writes.

Code Examples & CVEs

Demonstrative Examples

An attacker can render a memory line unusable by repeatedly causing a write to the memory line.

Below is example code from [REF-1058] that the user can execute repeatedly to cause line failure. W is the maximum associativity of any cache in the system; S is the size of the largest cache in the system.

AttackC++

// Do aligned alloc of (W+1) arrays each of size S 					while(1) { 					 					  for (ii = 0; ii < W + 1; ii++) 					   					    array[ii].element[0]++; 					   					 					}

An attacker can render a memory line unusable by repeatedly causing a write to the memory line.

GoodOther

Wear leveling must be used to even out writes to the device.

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-1246 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-1246, Improper Write Handling in Limited-write Non-Volatile Memories, 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 Improper Write Handling in Limited-write Non-Volatile Memories during Architecture and Design

MITRE associates mitigation with Architecture and Design, Implementation, and Testing; recorded impacts include DoS: Instability; the entry maps to CAPEC-212. Use these source-defined anchors to turn CWE-1246 into implementation, review, and verification checks for the affected component.

CWE-1246: Improper Write Handling in Limited-write Non-Volatile Memories — MITRE CWE

Triage CWE-1246 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-1246, Improper Write Handling in Limited-write Non-Volatile Memories, 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-1246

Apply MITRE's full root-cause mapping guidance when using CWE-1246, Improper Write Handling in Limited-write Non-Volatile Memories. 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-1246 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-1246, Improper Write Handling in Limited-write Non-Volatile Memories. 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-1246: Improper Write Handling in Limited-write Non-Volatile Memories?+

CWE-1246: Improper Write Handling in Limited-write Non-Volatile Memories is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product does not implement or incorrectly implements wear leveling operations in limited-write non-volatile memories. Non-volatile memories such as NAND Flash, EEPROM, etc. have individually erasable segments, each of which can be put through a limited number of program/erase or write cycles. For example, the device can only endure a limited number of writes, after which the device becomes unreliable. In order to wear out the cells in a uniform manner, non-volatile memory and storage products based on the above-mentioned technologies implement a technique called wear leveling. Once a set threshold is reached, wear leveling maps writes of a logical block to a different physical block. This prevents a single physical block from prematurely failing due to a high concentration of writes.

What are the security consequences of Improper Write Handling in Limited-write Non-Volatile Memories?+

If exploited, CWE-1246 (Improper Write Handling in Limited-write Non-Volatile Memories) it can compromise Availability, leading to outcomes such as DoS: Instability.

How do you prevent or mitigate Improper Write Handling in Limited-write Non-Volatile Memories?+

Recommended mitigations for CWE-1246 include: Include secure wear leveling algorithms and ensure they may not be bypassed.

Which programming languages are affected by Improper Write Handling in Limited-write Non-Volatile Memories?+

CWE-1246 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

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

A CWE (Common Weakness Enumeration) like CWE-1246 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-1246: Improper Write Handling in Limited-write Non-Volatile Memories

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