Affected: Apache Software Foundation Apache Tomcat

Improper Input Validation vulnerability.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.14, from 10.1.0-M1 through 10.1.49, from 9.0.0-M1 through 9.0.112.

The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Older EOL versions are not affected. Tomcat did not validate that the host name provided via the SNI extension was the same as the host name provided in the HTTP host header field. If Tomcat was configured with more than one virtual host and the TLS configuration for one of those hosts did not require client certificate authentication but another one did, it was possible for a client to bypass the client certificate authentication by sending different host names in the SNI extension and the HTTP host header field.

The vulnerability only applies if client certificate authentication is only enforced at the Connector. It does not apply if client certificate authentication is enforced at the web application.

Users are recommended to upgrade to version 11.0.15 or later, 10.1.50 or later or 9.0.113 or later, which fix the issue.

Affected: npm: qs

### Summary

The `arrayLimit` option in qs did not enforce limits for bracket notation (`a[]=1&a[]=2`), only for indexed notation (`a[0]=1`). This is a consistency bug; `arrayLimit` should apply uniformly across all array notations.

**Note:** The default `parameterLimit` of 1000 effectively mitigates the DoS scenario originally described. With default options, bracket notation cannot produce arrays larger than `parameterLimit` regardless of `arrayLimit`, because each `a[]=value` consumes one parameter slot. The severity has been reduced accordingly.

### Details

The `arrayLimit` option only checked limits for indexed notation (`a[0]=1&a[1]=2`) but did not enforce it for bracket notation (`a[]=1&a[]=2`).

**Vulnerable code** (`lib/parse.js:159-162`): ```javascript if (root === '[]' && options.parseArrays) { obj = utils.combine([], leaf); // No arrayLimit check } ```

**Working code** (`lib/parse.js:175`): ```javascript else if (index <= options.arrayLimit) { // Limit checked here obj = []; obj[index] = leaf; } ```

The bracket notation handler at line 159 uses `utils.combine([], leaf)` without validating against `options.arrayLimit`, while indexed notation at line 175 checks `index <= options.arrayLimit` before creating arrays.

### PoC

```javascript const qs = require('qs'); const result = qs.parse('a[]=1&a[]=2&a[]=3&a[]=4&a[]=5&a[]=6', { arrayLimit: 5 }); console.log(result.a.length); // Output: 6 (should be max 5) ```

**Note on parameterLimit interaction…