CVE-2021-30496 Denial of service in n/a

Medium 5.7 Published 20 Apr 2021 Updated 3 Aug 2024

Remote authenticated users can crash the Telegram iOS app by tricking victims into pasting specific messages, causing a denial of service.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2021-30496?

CVE-2021-30496 is a medium-severity denial of service vulnerability in n/a, published on 20 Apr 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

The Telegram app 7.6.2 for iOS allows remote authenticated users to cause a denial of service (application crash) if the victim pastes an attacker-supplied message (e.g., in the Persian language) into a channel or group. The crash occurs in MtProtoKitFramework. NOTE: the vendor's perspective is that "this behavior can't be considered a vulnerability."

Weakness: CWE-121

Which versions are affected by CVE-2021-30496?

It affects 1 product.

Products include Telegram Telegram.

How do I fix CVE-2021-30496?

No fix has been published for CVE-2021-30496 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-30496 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-30496 exists.

Sources

Also known as GHSA-25r9-gpg2-xcwf.