CWE-625: Permissive Regular Expression

BaseDraft

The product uses a regular expression that does not sufficiently restrict the set of allowed values.

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Extended Description

This effectively causes the regexp to accept substrings that match the pattern, which produces a partial comparison to the target. In some cases, this can lead to other weaknesses. Common errors include: not identifying the beginning and end of the target string using wildcards instead of acceptable character ranges others

Technical Details

Structure
Simple

Applicable To

Languages
PerlPHP
Platforms

Frequently Asked Questions

What is CWE-625: Permissive Regular Expression?+

CWE-625: Permissive Regular Expression is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product uses a regular expression that does not sufficiently restrict the set of allowed values. This effectively causes the regexp to accept substrings that match the pattern, which produces a partial comparison to the target. In some cases, this can lead to other weaknesses. Common errors include: not identifying the beginning and end of the target string using wildcards instead of acceptable character ranges others

What are the security consequences of Permissive Regular Expression?+

If exploited, CWE-625 (Permissive Regular Expression) it can compromise Access Control, leading to outcomes such as Bypass Protection Mechanism.

How do you prevent or mitigate Permissive Regular Expression?+

Recommended mitigations for CWE-625 include: When applicable, ensure that the regular expression marks beginning and ending string patterns, such as "/^string$/" for Perl.

Which programming languages are affected by Permissive Regular Expression?+

CWE-625 commonly affects Perl and PHP. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

What are real-world examples of Permissive Regular Expression?+

MITRE documents real CVEs mapped to CWE-625, including CVE-2021-22204, CVE-2006-1895, CVE-2002-2175, CVE-2006-4527 and CVE-2005-1949. 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-625 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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