CVE-2021-47793
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2026-01-16

Last updated on: 2026-01-16

Assigner: VulnCheck

Description
Telegram Desktop 2.9.2 contains a denial of service vulnerability that allows attackers to crash the application by sending an oversized message payload. Attackers can generate a 9 million byte buffer and paste it into the messaging interface to trigger an application crash.
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Meta Information
Published
2026-01-16
Last Modified
2026-01-16
Generated
2026-06-16
AI Q&A
2026-01-16
EPSS Evaluated
2026-06-15
NVD
CVE-2021-47793
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
telegram telegram_desktop 2.9.2
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-770 The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
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Executive Summary

This vulnerability in Telegram Desktop version 2.9.2 is a denial of service (DoS) issue caused by the application's improper handling of very large message payloads. An attacker can create and paste an oversized message, approximately 9 million bytes in size, into the messaging interface. This large input overwhelms the application, causing it to crash. [1, 3]

Impact Analysis

The impact of this vulnerability is that an attacker can cause the Telegram Desktop application to crash by sending or pasting an extremely large message payload. This results in a denial of service, disrupting the normal use of the application. The attack requires local access and user interaction but does not require any special privileges. [1, 3]

Detection Guidance

This vulnerability can be detected by attempting to reproduce the denial of service condition on Telegram Desktop 2.9.2. Specifically, you can generate a large payload (approximately 9 million bytes) and paste it into the Telegram Desktop messaging interface to see if the application crashes. A proof-of-concept involves creating a file with 9 million 'A' characters and pasting its content into the 'Saved Messages' chat input field. There are no specific network detection commands provided, as the attack is local and requires user interaction. [3]

Mitigation Strategies

Immediate mitigation steps include avoiding pasting or sending extremely large message payloads (around 9 million bytes) in Telegram Desktop version 2.9.2. Users should update Telegram Desktop to a version where this vulnerability is fixed if available. Additionally, exercising caution with messages and disabling or restricting the use of large clipboard pastes in the application can help prevent triggering the denial of service. [1, 3]

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