Full Disclosure mailing list archives
Re: Telegram authentication bypass
From: Dominik Schürmann <dominik () dominikschuermann de>
Date: Mon, 28 Apr 2014 21:12:01 +0200
Hello, like Telegram said, this is definitely out of normal security models! You assume that the client app has been compromised, e.g. by downloading an unofficial one. If you assume that, every crypto protocol out there is broken! What about downloading a forked Firefox version? Maybe it includes some MitM certificates... Nothing protects you against your attack... Regards from a suprised Dominik On Mon, 2014-04-28 at 11:17 +0200, jdiaz () cert inteco es wrote:
Hello, A security issue affecting Telegram instant messaging service has been made public by INTECO-CERT. Further details follow. ---------------------------------- Affected products and services: ---------------------------------- Telegram instant messaging service. ---------------------------------- Overview: ---------------------------------- Telegram authentication mechanism may be circumvented, since there is no way to verify the legitimacy of Telegrams public keys and thus if the client is communicating with a legitimate server. This may allow an attacker leveraging this issue (e.g. by distributing a slightly modified client) to obtain almost full control of the victim's account. Further, the behavior of the victims client is exactly the same than the behavior of a legitimate client. For a detailed analysis, including a PoC, visit: http://www.inteco.es/blogs/post/Seguridad/BlogSeguridad/Articulo_y_comentarios/telegram_authentication (blog post with extended abstract) or http://cert.inteco.es/extfrontinteco/img/File/intecocert/EstudiosInformes/INT_Telegram_EN.pdf (detailed research results). ---------------------------------- Timeline: ---------------------------------- 2014.03.07 - Initial contact with Telegram security team. 2014.03.10 - Telegram response informing that this issue is out of their security model. 2014.03.11 - Submission of PoC to Telegram security team. 2014.04.28 - Publication of research results. Sincerely, Jesus Diaz _______________________________________________ Sent through the Full Disclosure mailing list http://nmap.org/mailman/listinfo/fulldisclosure Web Archives & RSS: http://seclists.org/fulldisclosure/
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Current thread:
- Telegram authentication bypass jdiaz (Apr 28)
- Re: Telegram authentication bypass Dominik Schürmann (Apr 28)
- Re: Telegram authentication bypass jdiaz (Apr 29)
- Re: Telegram authentication bypass Mario Vilas (Apr 29)
- Re: Telegram authentication bypass Tony Arcieri (Apr 29)
- Re: Telegram authentication bypass jdiaz (Apr 29)
- Re: Telegram authentication bypass Hanno Böck (Apr 28)
- Re: Telegram authentication bypass Dominik Schürmann (Apr 28)