Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')
The product receives data from an HTTP agent/component, and it places this data in HTTP response headers without neutralizing CRLF sequences.
An attacker can inject CRLF sequences into HTTP headers to create additional headers or response body content. This can lead to cache poisoning, cross-site scripting, or other attacks.
如何修复此漏洞
基于 3 条 Shoulder 检测规则的 HTTP Response Splitting 预防策略。
Strip CRLF characters from user input before setting HTTP headers
package main - import "net/http" - - func handler(w http.ResponseWriter, r *http.Request) { - lang := r.URL.Query().Get("lang") - // Vulnerable: user input set as header value - w.Header().Set("Content-Language", lang) + import ( + "net/http" + "strings" + ) + + func sanitizeHeaderValue(s string) string { + s = strings.ReplaceAll(s, "\r", "") + s = strings.ReplaceAll(s, "\n", "") + return s + } + + func handler(w http.ResponseWriter, r *http.Request) { + lang := r.URL.Query().Get("lang") + // Safe: CRLF characters stripped + w.Header().Set("Content-Language", sanitizeHeaderValue(lang)) w.Write([]byte("OK")) }
Strip CRLF characters from user input before using in HTTP headers
- from flask import request, make_response - - @app.route('/download') - def download(): - filename = request.args.get('filename') - response = make_response("content") - response.headers['Content-Disposition'] = f'attachment; filename="{filename}"' + import re + from flask import request, make_response + + def sanitize_header(value): + return re.sub(r'[\r\n]', '', str(value)) + + @app.route('/download') + def download(): + filename = request.args.get('filename', '') + safe_filename = sanitize_header(filename) + response = make_response("content") + response.headers['Content-Disposition'] = f'attachment; filename="{safe_filename}"' return response
查找代码中的漏洞
使用Shoulder扫描代码中的Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')模式。 3 规则.
# Scan with Shoulder CLI npx @shoulderdev/cli trust --cwe=113 # Or scan entire project npx @shoulderdev/cli trust .
检测规则 (3)
代码审查中需要关注的内容
这些模式表明潜在的Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')漏洞。在代码审查和安全审计中注意查找。
扫描你的代码库: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')
Shoulder CLI 在整个代码库中找到易受攻击的模式。