Telegram

The "delete for" feature in Telegram before 5.11 on Android does not delete shared media files from the Telegram Images directory. In other words, there is a potentially misleading UI indication that a sender can remove a recipient's copy of a previously sent image (analogous to supported functionality in which a sender can remove a recipient's copy of a previously sent message).Show less

The Privacy > Phone Number feature in the Telegram app 5.10 for Android and iOS provides an incorrect indication that the access level is Nobody, because attackers can find these numbers via the Group Info feature, e.g., by adding a significant fraction of a region's assigned phone numbers.Show less

Telegram Desktop before 1.5.12 on Windows, and the Telegram applications for Android, iOS, and Linux, is vulnerable to an IDN homograph attack when displaying messages containing URLs. This occurs because the application produces a clickable link even if (for example) Latin and Cyrillic characters exist in the same domain name, and the available font has an identical representation of characters from different alphabets.Show less

An exploitable information disclosure vulnerability exists in the "Secret Chats" functionality of the Telegram Android messaging application version 4.9.0. The "Secret Chats" functionality allows a user to delete all traces of a chat, either by using a time trigger or by direct request. There is a bug in this functionality that leaves behind photos taken and shared on the secret chats, even after the chats are deleted. These photos will be stored in the device and accessible to all applications installed on the Android device.Show less

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" settingShow less

An issue was discovered in the org.telegram.messenger application 4.8.11 for Android. The FingerprintManager class for Biometric validation allows authentication bypass through the callback method from onAuthenticationFailed to onAuthenticationSucceeded with null, because the fingerprint API in conjunction with the Android keyGenerator class is not implemented. In other words, an attacker could authenticate with an arbitrary fingerprint. NOTE: the vendor indicates that this is not an attack of interest within the context of their threat model, which excludes Android devices on which rooting has occurredShow less

An issue was discovered in the org.telegram.messenger application 4.8.11 for Android. The Passcode feature allows authentication bypass via runtime manipulation that forces a certain method's return value to true. In other words, an attacker could authenticate with an arbitrary passcode. NOTE: the vendor indicates that this is not an attack of interest within the context of their threat model, which excludes Android devices on which rooting has occurredShow less