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Fencer Vulns
high 7.1

CVE-2021-31321 json

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Stack Based Overflow in the gray_split_cubic f…

published 2021-05-18 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18231

cvss
7.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits
0
none known

Summary

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Stack Based Overflow in the gray_split_cubic function of their custom fork of the rlottie library. A remote attacker might be able to overwrite Telegram's stack memory out-of-bounds on a victim device via a malicious animated sticker.

Patch / fix

  • telegram telegram 7.1.0
  • rlottie Debian 14, Debian 13, Debian 12 0.1+dfsg-2

debian advisories DEBIAN-CVE-2021-31321

  • rlottie Ubuntu 22.04 LTS 0.1+dfsg-2ubuntu0.1
  • rlottie Ubuntu Pro 20.04 LTS 0~git20200305.a717479+dfsg-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2021-31321

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Exploit prediction

1.10% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • shielder.it https://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/ referenced PoC, tagged "exploit" by a source, unverified
  • shielder.it https://www.shielder.it/advisories/telegram-rlottie-gray_split_cubic-stack-buffer-overflow/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:N/I:P/A:P

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.