CVE-2018-20436: SSRF
DISPUTED The "secret chat" feature in Telegram 4.9.1 for Android has a "side channel" in which Telegram servers send GET requests for URLs typed while composing a chat message, before that chat message is sent. There are also GET requests to other URLs on the same web server. This also affects one or more other Telegram products, such as Telegram Web-version 0.7.0. In addition, it can be interpreted as an SSRF issue. NOTE: a third party has reported that potentially unwanted behavior is caused by misconfiguration of the "Secret chats > Preview links" setting.
Affected Software
Event History
Frequently Asked Questions
What is the vulnerability ID for this issue?
The vulnerability ID for this issue is CVE-2018-20436.
What is the severity level of CVE-2018-20436?
CVE-2018-20436 has a severity level of 8.1 (high).
Which software versions are affected by CVE-2018-20436?
Telegram 4.9.1 for Android and Telegram Web 0.7.0 are affected by CVE-2018-20436.
What is the side channel in Telegram 4.9.1 for Android?
The side channel in Telegram 4.9.1 for Android is a mechanism in which Telegram servers send GET requests for URLs typed while composing a chat message, before that chat message is sent.
Are there any known exploits or proofs-of-concept for CVE-2018-20436?
Yes, there are known exploits and proofs-of-concept available for CVE-2018-20436. Please refer to the provided references for more information.