CWE-1261: Improper Handling of Single Event Upsets

Extended Description

Technology trends such as CMOS-transistor down-sizing, use of new materials, and system-on-chip architectures continue to increase the sensitivity of systems to soft errors. These errors are random, and their causes might be internal (e.g., interconnect coupling) or external (e.g., cosmic radiation). These soft errors are not permanent in nature and cause temporary bit flips known as single-event upsets (SEUs). SEUs are induced errors in circuits caused when charged particles lose energy by ionizing the medium through which they pass, leaving behind a wake of electron-hole pairs that cause temporary failures. If these failures occur in security-sensitive modules in a chip, it might compromise the security guarantees of the chip. For instance, these temporary failures could be bit flips that change the privilege of a regular user to root.

Code Examples & CVEs

Demonstrative Examples

This is an example from [REF-1089]. See the reference for full details of this issue.

Parity is error detecting but not error correcting.

BadOther

Due to single-event upsets, bits are flipped in memories.  As a result, memory-parity checks fail, which results in restart and a temporary denial of service of two to three minutes.

This is an example from [REF-1089]. See the reference for full details of this issue.

Parity is error detecting but not error correcting.

GoodOther

Using error-correcting codes could have avoided the restart caused by SEUs.

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-1261 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-1261, Improper Handling of Single Event Upsets, 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 Handling of Single Event Upsets during Architecture and Design

MITRE associates mitigation with Architecture and Design; recorded impacts include DoS: Crash, Exit, or Restart, DoS: Instability, Gain Privileges or Assume Identity, and Bypass Protection Mechanism; related weaknesses include CWE-1384, and CWE-1254. Use these source-defined anchors to turn CWE-1261 into implementation, review, and verification checks for the affected component.

CWE-1261: Improper Handling of Single Event Upsets — MITRE CWE

Triage CWE-1261 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-1261, Improper Handling of Single Event Upsets, 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-1261

Apply MITRE's full root-cause mapping guidance when using CWE-1261, Improper Handling of Single Event Upsets. 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-1261 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-1261, Improper Handling of Single Event Upsets. 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-1261: Improper Handling of Single Event Upsets?+

CWE-1261: Improper Handling of Single Event Upsets is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The hardware logic does not effectively handle when single-event upsets (SEUs) occur. Technology trends such as CMOS-transistor down-sizing, use of new materials, and system-on-chip architectures continue to increase the sensitivity of systems to soft errors. These errors are random, and their causes might be internal (e.g., interconnect coupling) or external (e.g., cosmic radiation). These soft errors are not permanent in nature and cause temporary bit flips known as single-event upsets (SEUs). SEUs are induced errors in circuits caused when charged particles lose energy by ionizing the medium through which they pass, leaving behind a wake of electron-hole pairs that cause temporary failures. If these failures occur in security-sensitive modules in a chip, it might compromise the security guarantees of the chip. For instance, these temporary failures could be bit flips that change the privilege of a regular user to root.

What are the security consequences of Improper Handling of Single Event Upsets?+

If exploited, CWE-1261 (Improper Handling of Single Event Upsets) it can compromise Availability and Access Control, leading to outcomes such as DoS: Crash, Exit, or Restart, DoS: Instability, Gain Privileges or Assume Identity and Bypass Protection Mechanism.

How do you prevent or mitigate Improper Handling of Single Event Upsets?+

Recommended mitigations for CWE-1261 include: Implement triple-modular redundancy around security-sensitive modules. SEUs mostly affect SRAMs. For SRAMs storing security-critical data, implement Error-Correcting-Codes (ECC) and Address Interleaving.

Which programming languages are affected by Improper Handling of Single Event Upsets?+

CWE-1261 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-1261 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-1261: Improper Handling of Single Event Upsets

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