CVE-2021-31323

Name: CVE-2021-31323
Creator: NVD / NIST
Published: 2021-05-18T20:15:07.863+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 1.27%

Last modified Jun 17, 2026

CVE-2021-31323 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Heap Buffer Overflow in the LottieParserImpl::parseDashProperty function of their custom fork of the rlottie library. A remote attacker might be able to access heap memory out-of-bounds on a victim device via a malicious animated sticker.. EPSS estimates a 1.27% chance of exploitation in the next 30 days.

Description

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Heap Buffer Overflow in the LottieParserImpl::parseDashProperty function of their custom fork of the rlottie library. A remote attacker might be able to access heap memory out-of-bounds on a victim device via a malicious animated sticker.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS Probability

1.27%

66.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Telegram	Telegram	< 7.1.0

References

https://www.shielder.it/advisories/telegram-rlottie-lottieparserimpl-parsedashproperty-heap-buffer-overflow/Exploit, Third Party Advisory
https://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/Exploit, Third Party Advisory
https://www.shielder.it/advisories/telegram-rlottie-lottieparserimpl-parsedashproperty-heap-buffer-overflow/Exploit, Third Party Advisory
https://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/Exploit, Third Party Advisory

Timeline

Published: May 18, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31323?

How severe is CVE-2021-31323?

CVE-2021-31323 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 1.27% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31323?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31323?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST