CVE-2021-31317
Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
5.5
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.
- Record
CVE-2021-31317- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:P/I:N/A:N - Weakness
- CWE-843
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-31317- Updated
- 2026-11-02
EUVDEUVD-2021-18227 No score
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.
- Record
EUVD-2021-18227- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-xf3x-92j4-vrpc No score
Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type...
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.
- Record
GHSA-xf3x-92j4-vrpc- Weakness
- CWE-843
- Updated
- 2026-11-02
OSV
5.5
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.
- Record
CVE-2021-31317- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-31317
5.5
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.
- Record
DEBIAN-CVE-2021-31317- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-31317
5.5
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.
- Record
UBUNTU-CVE-2021-31317- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVUSN-7198-1 No score
rlottie vulnerabilities
Paolo Giai discovered a series of stack-based overflow vulnerabilities in the blit and gray_render_cubic functions of a custom fork of the rlottie library. An attacker could possibly use this issue to leak sensitive information. This issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2021-31315, CVE-2021-31321)
Paolo Giai discovered a series of type confusion vulnerabilities in the VDasher constructor and the LOTCompLayerItem::LOTCompLayerItem function of a custom fork of the rlottie library. An attacker could possibly use this issue to leak sensitive information. This issue only affected Ubuntu 20.04 LTS. (CVE-2021-31317, CVE-2021-31318)
Paolo Giai discovered an integer overflow vulnerability in the LOTGradient::populate function of a custom fork of the rlottie library. An attacker could possibly use this issue to leak sensitive information. This issue only affected Ubuntu 20.04 LTS. (CVE-2021-31319)
Paolo Giai discovered a series of heap buffer overflow vulnerabilities in the VGradientCache::generateGradientColorTable and LOTGradient::populate functions of a custom fork of the rlottie library. An attacker could possibly use this issue to achieve remote code execution. This issue only affected Ubuntu 20.04 LTS. (CVE-2021-31320, CVE-2021-31322)
- Record
USN-7198-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
rlottieDebian:12 |
before 0.1+dfsg-2 | 0.1+dfsg-2 |
rlottieDebian:13 |
before 0.1+dfsg-2 | 0.1+dfsg-2 |
rlottieDebian:14 |
before 0.1+dfsg-2 | 0.1+dfsg-2 |
rlottieUbuntu:Pro:20.04:LTS |
before 0~git20200305.a717479+dfsg-1ubuntu0.1~esm1, plus listed versions 0~git20190721.24346d0+dfsg-20~git20190721.24346d0+dfsg-2build10~git20200305.a717479+dfsg-1 |
0~git20200305.a717479+dfsg-1ubuntu0.1~esm1 |
rlottieUbuntu:Pro:20.04:LTS From an advisory covering 7 CVEs |
before 0~git20200305.a717479+dfsg-1ubuntu0.1~esm1, plus listed versions 0~git20190721.24346d0+dfsg-20~git20190721.24346d0+dfsg-2build10~git20200305.a717479+dfsg-1 |
0~git20200305.a717479+dfsg-1ubuntu0.1~esm1 |
rlottieUbuntu:22.04:LTS From an advisory covering 7 CVEs |
before 0.1+dfsg-2ubuntu0.1, plus listed versions 0.1+dfsg-2 |
0.1+dfsg-2ubuntu0.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-31317 is a medium vulnerability (CVSS 5.5) in Telegram, published May 18, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.29%, the 70th percentile. Fixed in rlottie 0.1+dfsg-2.
References
shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface
shielder.it/advisories/telegram-rlottie-vdasher-vdasher-type-confusion
nvd.nist.gov/vuln/detail/CVE-2021-31317
github.com/advisories/GHSA-xf3x-92j4-vrpc
security-tracker.debian.org/tracker/CVE-2021-31317
ubuntu.com/security/CVE-2021-31317