What is the CVSS score of CVE-2021-31318?

CVE-2021-31318 has a CVSS 3.1 base score of 5.5 (Medium). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N. EPSS exploitation probability: 1.3%.

Is there a public PoC exploit available for CVE-2021-31318?

Yes, a public proof-of-concept exploit is available for CVE-2021-31318. Prioritise patching immediately. EPSS: 1.3%.

Telegram CVE-2021-31318

Q: Which versions of Telegram are affected by CVE-2021-31318?

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type Confusion in the LOTCompLayerItem::LOTCompLayerItem function of their custom fork of the rlottie.

MEDIUM

Access of Resource Using Incompatible Type (Type Confusion) (CWE-843)

2021-05-18 cve@mitre.org

Buffer Overflow Google Memory Corruption Apple Telegram

5.5

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-843 ASVS 5.0 V15 - Secure Coding and Architecture Type safety enforcement MITRE ATT&CK 1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	CVSS score of 5.5 (MEDIUM). Attack characteristics: local attack vector, low complexity, no privileges required, user interaction required. Public proof-of-concept exploit code is available.
Exploit ScenarioDerived	A local attacker with access to the system could execute arbitrary code by exploiting type confusion in the application. No authentication is required to exploit this vulnerability.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).

No patch listed yet 1.3% exploitation probability (EPSS)

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AnalysisAI

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type Confusion in the LOTCompLayerItem::LOTCompLayerItem function of their custom fork of the rlottie. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Enforce strict type checking, use type-safe languages, validate object types before operations.

Affects your stack

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Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Access of Resource Using Incompatible Type (Type Confusion) (CWE-843), which allows attackers to execute arbitrary code by exploiting type confusion in the application. Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type Confusion in the LOTCompLayerItem::LOTCompLayerItem function of their custom fork of the rlottie library. A remote attacker might be able to access heap memory out-of-bounds on a victim device via a malicious animated sticker. Affected products include: Telegram.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 5.5 MEDIUM

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

DescriptionNVD

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type Confusion in the LOTCompLayerItem::LOTCompLayerItem function of their custom fork of the rlottie library. A remote attacker might be able to access heap memory out-of-bounds on a victim device via a malicious animated sticker.

Threat Intelligence Overview

EPSS Score

1.3%

Top 33% exploitable

Exploit

POC

Public exploit code exists

Data Quality

2 sources

Confidence: Low

NVD

CVE.org

EPSS

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity MEDIUM

CISA KEV No

Public POC Yes

EPSS 1.3%

Patch available No

Active threat No

Deciding rule

MEDIUM severity (CVSS 4.0-6.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

Poc

System Exposure· derived

Small

Automatable· derived

Human Impact· derived

Medium

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +1

CVSS: +28

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Buffer Overflow HIGH

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Memory Corruption HIGH

Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.