CVE-2021-31317 : Vulnerability Insights and Analysis

Telegram Android version less than 7.1.0 (2090), Telegram iOS version less than 7.1, and Telegram macOS version less than 7.1 are impacted by a Type Confusion vulnerability in the VDasher constructor of their custom fork of the rlottie library. This flaw could allow a remote attacker to exploit and access Telegram's heap memory out-of-bounds on a victim device via a malicious animated sticker.

Understanding CVE-2021-31317

This section delves into the key details surrounding CVE-2021-31317.

What is CVE-2021-31317?

CVE-2021-31317 relates to a Type Confusion vulnerability in Telegram's Android, iOS, and macOS versions, potentially enabling unauthorized access to a victim device's heap memory through a malicious animated sticker.

The Impact of CVE-2021-31317

The vulnerability in Telegram can be exploited by a remote attacker, compromising the victim's device's memory through crafted animated stickers. This could lead to unauthorized access to sensitive data.

Technical Details of CVE-2021-31317

In this section, we explore the technical aspects of CVE-2021-31317.

Vulnerability Description

The Type Confusion vulnerability in the VDasher constructor of rlottie library in Telegram's Android, iOS, and macOS versions allows attackers to access heap memory out-of-bounds via a malicious animated sticker.

Affected Systems and Versions

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are confirmed to be affected by this vulnerability.

Exploitation Mechanism

Exploiting this vulnerability involves leveraging the Type Confusion issue in the VDasher constructor to manipulate heap memory through specially crafted animated stickers.

Mitigation and Prevention

This section provides guidance on addressing CVE-2021-31317.

Immediate Steps to Take

Users are advised to update their Telegram apps to versions 7.1.0 (2090) and above to mitigate the risk of exploitation. Avoid interacting with untrusted or suspicious animated stickers to prevent potential attacks.

Long-Term Security Practices

Practicing caution while downloading and interacting with media content within messaging apps can help mitigate the risk of similar vulnerabilities being exploited.

Patching and Updates

Regularly update Telegram applications on all devices to the latest versions to ensure that security patches are applied promptly and vulnerabilities are mitigated effectively.