CWE-836: Use of Password Hash Instead of Password for Authentication

BaseIncomplete

The product records password hashes in a data store, receives a hash of a password from a client, and compares the supplied hash to the hash obtained from the data store.

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Extended Description

Some authentication mechanisms rely on the client to generate the hash for a password, possibly to reduce load on the server or avoid sending the password across the network. However, when the client is used to generate the hash, an attacker can bypass the authentication by obtaining a copy of the hash, e.g. by using SQL injection to compromise a database of authentication credentials, or by exploiting an information exposure. The attacker could then use a modified client to replay the stolen hash without having knowledge of the original password. As a result, the server-side comparison against a client-side hash does not provide any more security than the use of passwords without hashing.

Technical Details

Structure
Simple

Applicable To

Languages
Not Language-Specific
Platforms

Frequently Asked Questions

What is CWE-836: Use of Password Hash Instead of Password for Authentication?+

CWE-836: Use of Password Hash Instead of Password for Authentication is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product records password hashes in a data store, receives a hash of a password from a client, and compares the supplied hash to the hash obtained from the data store. Some authentication mechanisms rely on the client to generate the hash for a password, possibly to reduce load on the server or avoid sending the password across the network. However, when the client is used to generate the hash, an attacker can bypass the authentication by obtaining a copy of the hash, e.g. by using SQL injection to compromise a database of authentication credentials, or by exploiting an information exposure. The attacker could then use a modified client to replay the stolen hash without having knowledge of the original password. As a result, the server-side comparison against a client-side hash does not provide any more security than the use of passwords without hashing.

What are the security consequences of Use of Password Hash Instead of Password for Authentication?+

If exploited, CWE-836 (Use of Password Hash Instead of Password for Authentication) it can compromise Access Control, leading to outcomes such as Bypass Protection Mechanism and Gain Privileges or Assume Identity.

Which programming languages are affected by Use of Password Hash Instead of Password for Authentication?+

CWE-836 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

What are real-world examples of Use of Password Hash Instead of Password for Authentication?+

MITRE documents real CVEs mapped to CWE-836, including CVE-2009-1283 and CVE-2005-3435. 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-836 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.

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