Chi tiết CWE-343

CWE-343

Predictable Value Range from Previous Values
2006-07-19
00h00 +00:00
Draft
2026-10-28
00h00 +00:00
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Quản lý thông báo

Tên: Predictable Value Range from Previous Values

The product's random number generator produces a series of values which, when observed, can be used to infer a relatively small range of possibilities for the next value that could be generated.

Thông tin chung

Các cách xuất hiện

Architecture and Design
Implementation

Nền tảng áp dụng

Ngôn ngữ

Lớp: Not Language-Specific (Undetermined)

Hậu quả phổ biến

Phạm vi Tác động Khả năng xảy ra
OtherVaries by Context

Ghi chú: In some cases, an attacker cannot predict the exact value that will be produced next, but can narrow down the possibilities significantly. This reduces the amount of effort to perform a brute force attack.

Các biện pháp giảm thiểu tiềm năng

Phases : Architecture and Design // Implementation
The output of a random number generator should not be predictable based on observations of previous values.
Phases : Implementation
Increase the entropy used to seed a PRNG.
Phases : Architecture and Design // Requirements
Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").
Phases : Implementation
Use a PRNG that periodically re-seeds itself using input from high-quality sources, such as hardware devices with high entropy. However, do not re-seed too frequently, or else the entropy source might block.

Ghi chú ánh xạ lỗ hổng

Lý do : This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Bình luận : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Ghi chú

As of CWE 4.5, terminology related to randomness, entropy, and predictability can vary widely. Within the developer and other communities, "randomness" is used heavily. However, within cryptography, "entropy" is distinct, typically implied as a measurement. There are no commonly-used definitions, even within standards documents and cryptography papers. Future versions of CWE will attempt to define these terms and, if necessary, distinguish between them in ways that are appropriate for different communities but do not reduce the usability of CWE for mapping, understanding, or other scenarios.

Tài liệu tham khảo

REF-267

FIPS PUB 140-2: SECURITY REQUIREMENTS FOR CRYPTOGRAPHIC MODULES
Information Technology Laboratory, National Institute of Standards and Technology.
https://csrc.nist.gov/files/pubs/fips/140-2/upd2/final/docs/fips1402.pdf

REF-320

Strange Attractors and TCP/IP Sequence Number Analysis
Michal Zalewski.
https://lcamtuf.coredump.cx/oldtcp/tcpseq.html

REF-44

24 Deadly Sins of Software Security
Michael Howard, David LeBlanc, John Viega.

Gửi

Tên Tổ chức Ngày Ngày phát hành Version
PLOVER 2006-07-19 +00:00 2006-07-19 +00:00 Draft 3

Sửa đổi

Tên Tổ chức Ngày Bình luận
Eric Dalci Cigital 2008-07-01 +00:00 updated Time_of_Introduction
CWE Content Team MITRE 2008-09-08 +00:00 updated Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2008-10-14 +00:00 updated Description
CWE Content Team MITRE 2009-03-10 +00:00 updated Potential_Mitigations
CWE Content Team MITRE 2009-12-28 +00:00 updated Potential_Mitigations
CWE Content Team MITRE 2010-06-21 +00:00 updated Potential_Mitigations
CWE Content Team MITRE 2011-06-01 +00:00 updated Common_Consequences
CWE Content Team MITRE 2011-06-27 +00:00 updated Common_Consequences
CWE Content Team MITRE 2011-09-13 +00:00 updated Potential_Mitigations, References
CWE Content Team MITRE 2012-05-11 +00:00 updated References, Relationships
CWE Content Team MITRE 2012-10-30 +00:00 updated Potential_Mitigations
CWE Content Team MITRE 2017-11-08 +00:00 updated Applicable_Platforms, References
CWE Content Team MITRE 2020-02-24 +00:00 updated Relationships
CWE Content Team MITRE 2021-07-20 +00:00 updated Maintenance_Notes
CWE Content Team MITRE 2023-01-31 +00:00 updated Description
CWE Content Team MITRE 2023-04-27 +00:00 updated References, Relationships
CWE Content Team MITRE 2023-06-29 +00:00 updated Mapping_Notes
CWE Content Team MITRE 2025-09-09 +00:00 updated References
CWE Content Team MITRE 2025-12-11 +00:00 updated Weakness_Ordinalities
CWE Content Team MITRE 2026-10-28 +00:00 updated Common_Consequences, Demonstrative_Examples, Description, Potential_Mitigations