Regular Expression Denial of Service

Description

The regex used to compare with user-supplied input is vulnerable to regular expression denial of service, which can cause the application to become unresponsive or crash.

Examples

Insecure Code

app.get('/', (req, res) => { const regex = /^.*$/; regex.test(req.query.input); res.send('Hello World'); });

Secure Code

app.get('/', (req, res) => { const regex = /^[a-zA-Z0-9]+$/; regex.test(req.query.input); res.send('Hello World'); });

Remediation

Use a safe regex pattern or validate user input to prevent malicious regex patterns.

Rule Details

Field	Value
ID	CODE-0366
Category	Injection
Severity	MEDIUM
CWE	CWE-185
Confidence	HIGH
Impact	MEDIUM
Likelihood	MEDIUM
Exploitability	EASY
Tags	regex, denial of service
OWASP	A6:2017-Security Misconfiguration, A05:2021-Security Misconfiguration

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