名前: Use of a One-Way Hash with a Predictable Salt

The product uses a one-way cryptographic hash against an input that should not be reversible, such as a password, but the product uses a predictable salt as part of the input.

一般情報

背景の詳細

導入モード

Implementation : REALIZATION: This weakness is caused during implementation of an architectural security tactic.

適用可能なプラットフォーム

言語

クラス： Not Language-Specific (Undetermined)

一般的な結果

スコープ	影響	可能性
Access Control	Bypass Protection Mechanism 注記：This makes it easier for attackers to pre-compute the hash value using dictionary attack techniques such as rainbow tables, effectively disabling the protection that an unpredictable salt would provide.

観察された例

参考文献	説明
CVE-2008-4905	Blogging software uses a hard-coded salt when calculating a password hash.
CVE-2002-1657	Database server uses the username for a salt when encrypting passwords, simplifying brute force attacks.
CVE-2001-0967	Server uses a constant salt when encrypting passwords, simplifying brute force attacks.
CVE-2005-0408	Chain: product generates predictable MD5 hashes using a constant value combined with username, allowing authentication bypass.

潜在的な緩和策

Phases : Architecture and Design
Phases : Implementation
If a technique that requires extra computational effort can not be implemented, then for each password that is processed, generate a new random salt using a strong random number generator with unpredictable seeds. Add the salt to the plaintext password before hashing it. When storing the hash, also store the salt. Do not use the same salt for every password.

検出方法

Automated Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
有効性 : High

脆弱性マッピングノート

理由 : This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
コメント : 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.

ノート

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.

参考文献

REF-291

bcrypt
Johnny Shelley.
https://bcrypt.sourceforge.net/

REF-292

Tarsnap - The scrypt key derivation function and encryption utility
Colin Percival.
http://www.tarsnap.com/scrypt.html

REF-293

RFC2898 - PKCS #5: Password-Based Cryptography Specification Version 2.0
B. Kaliski.
https://www.rfc-editor.org/rfc/rfc2898

REF-294

How To Safely Store A Password
Coda Hale.
https://codahale.com/how-to-safely-store-a-password/

REF-295

How Companies Can Beef Up Password Security (interview with Thomas H. Ptacek)
Brian Krebs.
https://krebsonsecurity.com/2012/06/how-companies-can-beef-up-password-security/

REF-632

Enough With The Rainbow Tables: What You Need To Know About Secure Password Schemes
Thomas Ptacek.
http://hashphp.org/hashing.html

REF-633

The Importance of Being Canonical
Robert Graham.
https://blog.erratasec.com/2009/02/importance-of-being-canonical.html#.ZCbyY7LMJPY

REF-634

Password Hashing
James McGlinn.
https://privacyaustralia.net/phpsec/articles/password-hashing/

REF-635

Rainbow Hash Cracking
Jeff Atwood.
https://blog.codinghorror.com/rainbow-hash-cracking/

REF-636

Speed Hashing
Jeff Atwood.
https://blog.codinghorror.com/speed-hashing/

REF-637

Rainbow table
https://en.wikipedia.org/wiki/Rainbow_table

REF-7

Writing Secure Code
Michael Howard, David LeBlanc.
https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223

REF-62

The Art of Software Security Assessment
Mark Dowd, John McDonald, Justin Schuh.

登録情報

名前	組織	日付	リリース日	Version
CWE Content Team	MITRE	2009-03-03 +00:00	2009-03-10 +00:00	1.3

変更履歴

名前	組織	日付	コメント
CWE Content Team	MITRE	2009-10-29 +00:00	updated Observed_Examples, Relationships
CWE Content Team	MITRE	2010-02-16 +00:00	updated References
CWE Content Team	MITRE	2011-03-29 +00:00	updated Observed_Examples
CWE Content Team	MITRE	2011-06-01 +00:00	updated Common_Consequences
CWE Content Team	MITRE	2012-05-11 +00:00	updated References, Relationships
CWE Content Team	MITRE	2012-10-30 +00:00	updated Potential_Mitigations, References
CWE Content Team	MITRE	2013-02-21 +00:00	updated Description, Potential_Mitigations, References, Relationships, Type
CWE Content Team	MITRE	2014-02-18 +00:00	updated Potential_Mitigations, References
CWE Content Team	MITRE	2014-07-30 +00:00	updated Relationships
CWE Content Team	MITRE	2017-01-19 +00:00	updated Relationships
CWE Content Team	MITRE	2017-11-08 +00:00	updated Modes_of_Introduction, References, Relationships
CWE Content Team	MITRE	2018-03-27 +00:00	updated References
CWE Content Team	MITRE	2019-06-20 +00:00	updated Type
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	2021-10-28 +00:00	updated Relationships
CWE Content Team	MITRE	2023-01-31 +00:00	updated Description
CWE Content Team	MITRE	2023-04-27 +00:00	updated Detection_Factors, 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 Applicable_Platforms, Relationships, Weakness_Ordinalities
CWE Content Team	MITRE	2026-10-28 +00:00	updated Common_Consequences, Description, Potential_Mitigations

CWE-760 詳細

CWE-760