hacktricks/pentesting/pentesting-imap.md

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# 143,993 - Pentesting IMAP
## Internet Message Access Protocol
As its name implies, IMAP allows you to **access your email messages wherever you are**; much of the time, it is accessed via the Internet. Basically, email **messages are stored on servers**. Whenever you check your inbox, your email client contacts the server to connect you with your messages. When you read an email message using IMAP, **you aren't actually downloading** or storing it on your computer; instead, you are **reading it off of the server**. As a result, it's possible to check your email from **several different devices** without missing a thing.
By default, the IMAP protocol works on two ports:
* **Port 143** - this is the default IMAP non-encrypted port
* **Port 993** - this is the port you need to use if you want to connect using IMAP securely
```text
PORT STATE SERVICE REASON
143/tcp open imap syn-ack
```
## Banner grabbing
```bash
nc -nv <IP> 143
openssl s_client -connect <IP>:993 -quiet
```
### NTLM Auth - Information disclosure
If the server supports NTLM auth \(Windows\) you can obtain sensitive info \(versions\):
```text
root@kali: telnet example.com 143
* OK The Microsoft Exchange IMAP4 service is ready.
>> a1 AUTHENTICATE NTLM
+
>> TlRMTVNTUAABAAAAB4IIAAAAAAAAAAAAAAAAAAAAAAA=
+ TlRMTVNTUAACAAAACgAKADgAAAAFgooCBqqVKFrKPCMAAAAAAAAAAEgASABCAAAABgOAJQAAAA9JAEkAUwAwADEAAgAKAEkASQBTADAAMQABAAoASQBJAFMAMAAxAAQACgBJAEkAUwAwADEAAwAKAEkASQBTADAAMQAHAAgAHwMI0VPy1QEAAAAA
```
Or **automate** this with **nmap** plugin `imap-ntlm-info.nse`
### [IMAP Bruteforce](../brute-force.md#imap)
## Syntax
```text
Login
A1 LOGIN username password
Values can be quoted to enclose spaces and special characters. A " must then be escape with a \
A1 LOGIN "username" "password"
List Folders/Mailboxes
A1 LIST "" *
A1 LIST INBOX *
A1 LIST "Archive" *
Create new Folder/Mailbox
A1 CREATE INBOX.Archive.2012
A1 CREATE "To Read"
Delete Folder/Mailbox
A1 DELETE INBOX.Archive.2012
A1 DELETE "To Read"
Rename Folder/Mailbox
A1 RENAME "INBOX.One" "INBOX.Two"
List Subscribed Mailboxes
A1 LSUB "" *
Status of Mailbox (There are more flags than the ones listed)
A1 STATUS INBOX (MESSAGES UNSEEN RECENT)
Select a mailbox
A1 SELECT INBOX
List messages
A1 FETCH 1:* (FLAGS)
A1 UID FETCH 1:* (FLAGS)
Retrieve Message Content
A1 FETCH 2 body[text]
A1 FETCH 2 all
A1 UID FETCH 102 (UID RFC822.SIZE BODY.PEEK[])
Close Mailbox
A1 CLOSE
Logout
A1 LOGOUT
```
From [here](https://donsutherland.org/crib/imap)
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## CURL
Basic navigation is possible with [CURL](https://ec.haxx.se/usingcurl/usingcurl-reademail#imap), but the documentation is light on details so checking the [source](https://github.com/curl/curl/blob/master/lib/imap.c) is recommended for precise details.
1. Listing mailboxes \(imap command `LIST "" "*"`\)
```bash
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$ curl -k 'imaps://1.2.3.4/' --user user:pass
```
2. Listing messages in a mailbox \(imap command `SELECT INBOX` and then `SEARCH ALL`\)
```bash
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$ curl -k 'imaps://1.2.3.4/INBOX?ALL' --user user:pass
```
The result of this search is a list of message indicies.
Its also possible to provide more complex search terms. e.g. searching for drafts with password in mail body:
```bash
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$ curl -k 'imaps://1.2.3.4/Drafts?TEXT password' --user user:pass
```
A nice overview of the search terms possible is located [here](https://www.atmail.com/blog/imap-commands/).
3. Downloading a message \(imap command `SELECT Drafts` and then `FETCH 1 BODY[]`\)
```bash
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$ curl -k 'imaps://1.2.3.4/Drafts;MAILINDEX=1' --user user:pass
```
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The mail index will be the same index returned from the search operation.
It is also possible to use `UID` \(unique id\) to access messages, however it is less conveniant as the search command needs to be manually formatted. E.g.
```bash
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$ curl -k 'imaps://1.2.3.4/INBOX' -X 'UID SEARCH ALL' --user user:pass
$ curl -k 'imaps://1.2.3.4/INBOX;UID=1' --user user:pass
```
Also, possible to download just parts of a message, e.g. subject and sender of first 5 messages \(the `-v` is required to see the subject and sender\):
```bash
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$ curl -k 'imaps://1.2.3.4/INBOX' -X 'FETCH 1:5 BODY[HEADER.FIELDS (SUBJECT FROM)]' --user user:pass -v 2>&1 | grep '^<'
```
Although, its probably cleaner to just write a little for loop:
```text
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for m in {1..5}; do
echo $m
curl "imap://1.2.3.4/INBOX;MAILINDEX=$m;SECTION=HEADER.FIELDS%20(SUBJECT%20FROM)" --user user:pass
done
```
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## Shodan
* `port:143 CAPABILITY`
* `port:993 CAPABILITY`