CVE-2021-31317 json
Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type Confusion in the VDasher constructor of t…
published 2021-05-18 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18227
- cvss
- 5.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.3%
- EPSS 1.3% chance of exploitation in 30 days, percentile 70%
- 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 Type Confusion in the VDasher constructor of their custom fork of the rlottie library. A remote attacker might be able to access Telegram's heap 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-2021-31317
- rlottie Ubuntu Pro 20.04 LTS 0~git20200305.a717479+dfsg-1ubuntu0.1~esm1
ubuntu advisories UBUNTU-CVE-2021-31317
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
1.29% chance of exploitation in the next 30 days, higher than 70% 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-vdasher-vdasher-type-confusion/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:P/I:N/A:N |
Classification
- Weakness
-
- CWE-843 Access of Resource Using Incompatible Type
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-vdasher-vdasher-type-confusion/
exploit, third-party-advisory
Sources
- CVE List CVE-2021-31317
- NVD CVE-2021-31317
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.