CVE-2021-31320 json
Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Heap Buffer Overflow in the VGradientCache::ge…
published 2021-05-18 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18230
- cvss
- 7.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 68%
- 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 Heap Buffer Overflow in the VGradientCache::generateGradientColorTable function of their custom fork of the rlottie library. A remote attacker might be able to overwrite heap memory out-of-bounds on a victim device via a malicious animated sticker.
Patch / fix
- telegram telegram 7.1.0
- rlottie Ubuntu Pro 20.04 LTS 0~git20200305.a717479+dfsg-1ubuntu0.1~esm1
ubuntu advisories UBUNTU-CVE-2021-31320
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
1.22% chance of exploitation in the next 30 days, higher than 68% 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-vgradientcache-generategradientcolortable-heap-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
-
- CWE-787 Out-of-bounds Write
References
-
shielder.it
/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/
exploit, third-party-advisory
-
shielder.it
/advisories/telegram-rlottie-vgradientcache-generategradientcolortable-heap-buffer-overflow/
exploit, third-party-advisory
Sources
- CVE List CVE-2021-31320
- NVD CVE-2021-31320
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