CVE-2021-31321: telegram Out-of-bounds Write
Vulnerability summary
CVE-2021-31321 is a high (CVSS 7.1) Out-of-bounds Write vulnerability in telegram. EPSS estimates a 1.10% chance of exploitation in the next 30 days, higher than 65.1% of scored vulnerabilities. 2 public exploits are recorded.
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 18-05-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
EPSS trend
Probability
1.10%
Chance of exploitation in the next 30 days
Percentile
65%
Versus all other CVEs
30-day change
0.00 pp
From 1.10% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
2 foundExploit Reference (shielder.it)
Maturity: unknown
Exploit Reference (shielder.it)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Debian1 product
- rlottie< 0.1+dfsg-2
Telegram1 product
- telegram< 7.1.0
Ubuntu1 product
- rlottie< 0~git20200305.a717479+dfsg-1ubuntu0.1~esm1 | < 0.1+dfsg-2ubuntu0.1
3 vendors · 3 products
References
6 links- www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/X Refsource MISCExploitThird Party Advisory
- www.shielder.it/advisories/telegram-rlottie-gray_split_cubic-stack-buffer-overflow/X Refsource MISCREPORTExploitThird Party Advisory
