CriticalFile-scopeJavaScript / TypeScript Plug & play

Prevent open redirect vulnerabilities in DOM updates

Ensure that URLs used in redirection are properly validated and restricted to trusted domains. Open redirects can be exploited to redirect users to malicious sites.

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Why this matters

Open redirects allow attackers to manipulate URLs and redirect users to malicious sites. Always validate and restrict redirection URLs to trusted domains.

Bad vs. good

Side-by-side examples engineers can pattern-match during review.

Avoid

const queryParams = new URLSearchParams(document.location.search);
const redirectUrl = queryParams.get("url");
document.location = redirectUrl; // Noncompliant

Prefer

const queryParams = new URLSearchParams(document.location.search);
const redirectUrl = queryParams.get("url");

if (redirectUrl.startsWith("https://www.example.com/")) {
    document.location = redirectUrl;
}

More snippets

Bad

const queryParams = new URLSearchParams(document.location.search);
const redirectUrl = queryParams.get("url");
document.location = redirectUrl; // Noncompliant

Good

const queryParams = new URLSearchParams(document.location.search);
const redirectUrl = queryParams.get("url");

if (redirectUrl.startsWith("https://www.example.com/")) {
    document.location = redirectUrl;
}

Related rules

From the same buckets as this rule.

Critical
Always sanitize user inputs
Check if user inputs are sanitized before being used in rendering or database queries. Unsanitized inputs can lead to injection vulnerabilities like XSS or SQL injection.
security-hardening
Critical
Always Verify Server Certificates in SSL/TLS Connections
Ensure that SSL/TLS certificate validation is always enabled to prevent Man-in-the-Middle (MitM) attacks.
security-hardening
Critical
Avoid modifying built-in prototypes
Detect modifications to built-in prototypes. Modifying built-in objects can lead to compatibility issues and unexpected behavior. Recommend creating helper functions instead.
maintainabilitysecurity-hardening

Bad vs. good

Side-by-side examples engineers can pattern-match during review.

Avoid

const queryParams = new URLSearchParams(document.location.search);
const redirectUrl = queryParams.get("url");
document.location = redirectUrl; // Noncompliant

Prefer

const queryParams = new URLSearchParams(document.location.search);
const redirectUrl = queryParams.get("url");

if (redirectUrl.startsWith("https://www.example.com/")) {
    document.location = redirectUrl;
}

More snippets

Bad

const queryParams = new URLSearchParams(document.location.search);
const redirectUrl = queryParams.get("url");
document.location = redirectUrl; // Noncompliant

Good

const queryParams = new URLSearchParams(document.location.search);
const redirectUrl = queryParams.get("url");

if (redirectUrl.startsWith("https://www.example.com/")) {
    document.location = redirectUrl;
}

Related rules

From the same buckets as this rule.

Critical

Always sanitize user inputs

Check if user inputs are sanitized before being used in rendering or database queries. Unsanitized inputs can lead to injection vulnerabilities like XSS or SQL injection.

security-hardening

Critical

Always Verify Server Certificates in SSL/TLS Connections

Ensure that SSL/TLS certificate validation is always enabled to prevent Man-in-the-Middle (MitM) attacks.

security-hardening

Critical

Avoid modifying built-in prototypes

Detect modifications to built-in prototypes. Modifying built-in objects can lead to compatibility issues and unexpected behavior. Recommend creating helper functions instead.

maintainabilitysecurity-hardening