Inefficient Regular Expression Complexity (CWE-1333)

Inefficient Regular Expression Complexity

The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.

Certain regular expression patterns can take exponential time to evaluate on certain inputs (ReDoS). Attackers can craft inputs that cause the regex engine to consume excessive CPU time, leading to denial of service.

Prevalência

Média

3 linguagens cobertas

Impacto

Alto

1 regras de severidade alta

Prevenção

Documentada

3 exemplos de correção

2 Prevenção

Como corrigir esta vulnerabilidade

Estratégias de prevenção para ReDoS baseadas em 3 regras de detecção do Shoulder.

🐹 Go Ver tudo Go detalhes →

Regular Expression Denial of Service MEDIUM

Avoid nested quantifiers in regex; use specific character classes instead

+1 -1 go

- re := regexp.MustCompile("(a+)+b")
+ re := regexp.MustCompile("^[a-z]+b$")

🟨 JavaScript Ver tudo JavaScript detalhes →

Regular Expression Denial of Service (ReDoS) HIGH

Avoid nested quantifiers in regex and validate input length before matching

+6 -2 javascript

- const emailRegex = /^([a-zA-Z0-9]+\.)+[a-zA-Z]{2,}$/;
- if (emailRegex.test(req.body.email)) {
+ const validator = require('validator');
+ 
+ if (req.body.email.length > 254) {
+   return res.status(400).json({ error: 'Input too long' });
+ }
+ if (validator.isEmail(req.body.email)) {
    processEmail(req.body.email);
  }

🐍 Python Ver tudo Python detalhes →

Regular Expression Denial of Service (ReDoS) MEDIUM

Replace nested quantifiers with simple patterns and bounded repetition

+1 -1 python

  import re
  
- email_pattern = re.compile(r'^([a-zA-Z0-9._-]+)+@[a-zA-Z0-9.-]+$')
+ email_pattern = re.compile(r'^[a-zA-Z0-9._-]{1,64}@[a-zA-Z0-9.-]{1,255}$')
  
  def validate_email(email):
      return email_pattern.match(email)

Práticas-chave

Use exponential time complexity when matching certain inputs

3 Detecção

Encontre vulnerabilidades no seu código

Use o Shoulder para escanear seu código em busca de padrões Inefficient Regular Expression Complexity. 3 regras.

terminal

# Scan with Shoulder CLI
npx @shoulderdev/cli trust --cwe=1333

# Or scan entire project
npx @shoulderdev/cli trust .

Regras de Detecção (3)

🐹 Go 1 rules

Regular Expression Denial of Service MEDIUM

Regex pattern with nested quantifiers causes catastrophic backtracking.

🟨 Javascript 1 rules

Regular Expression Denial of Service (ReDoS) HIGH

Detects potentially catastrophic regular expressions that could lead to ReDoS attacks. ReDoS occurs when regular expressions with certain patterns cause exponential backtracking, leading to excessive CPU consumption. Evil regexes typically contain: 1. Nested quantifiers (e.g., (a+)+, (a*)*) 2. Alternation with overlapping patterns (e.g., (a|ab)*, (a|a)*) 3. Grouping with repetition where the group can match the same input in multiple ways 4. Complex patterns with overlapping possibilities that

🔷 Typescript 1 rules

Regular Expression Denial of Service (ReDoS) HIGH

🐍 Python 1 rules

Regular Expression Denial of Service (ReDoS) MEDIUM

Detects regular expressions with catastrophic backtracking patterns that can cause exponential time complexity when matching certain inputs. Attackers can exploit this to cause denial of service. Use simpler patterns or set timeouts.

4 Sinais de Alerta

O que observar nas revisões de código

Estes padrões indicam vulnerabilidades potenciais de Inefficient Regular Expression Complexity. Procure-os durante revisões de código e auditorias de segurança.

🟠

potentially catastrophic regular expressions that could lead to ReDoS attacks javascript-regex-dos

🟡

regular expressions with catastrophic backtracking patterns that can cause exponential time complexi python-redos

🔍

Escaneie seu código para Inefficient Regular Expression Complexity

O Shoulder CLI encontra padrões vulneráveis em todo o seu código.

npx shoulder trust Ver todas as regras