What is the CVSS score of CVE-2021-31321?

CVE-2021-31321 has a CVSS 3.1 base score of 7.1 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H. EPSS exploitation probability: 1.1%.

Is there a public PoC exploit available for CVE-2021-31321?

Yes, a public proof-of-concept exploit is available for CVE-2021-31321. Prioritise patching immediately. EPSS: 1.1%.

Telegram CVE-2021-31321

Q: Which versions of Telegram are affected by CVE-2021-31321?

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.

HIGH

Out-of-bounds Write (CWE-787)

2021-05-18 cve@mitre.org

Buffer Overflow Apple Memory Corruption Google Telegram

7.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.1 HIGH

AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

May 18, 2021 - 20:15 nvd

HIGH 7.1

DescriptionNVD

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.

AnalysisAI

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. Rated high severity (CVSS 7.1), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Out-of-bounds Write (CWE-787), which allows attackers to write data beyond allocated buffer boundaries leading to code execution or crashes. 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. Affected products include: Telegram.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate write boundaries, use memory-safe languages, enable compiler protections (ASLR, stack canaries).