What is the CVSS score of CVE-2021-30354?

CVE-2021-30354 has a CVSS 3.1 base score of 8.6 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H. EPSS exploitation probability: 7.0%.

Is there a public PoC exploit available for CVE-2021-30354?

Yes, a public proof-of-concept exploit is available for CVE-2021-30354. Prioritise patching immediately. EPSS: 7.0%.

Amazon CVE-2021-30354

HIGH

Integer Overflow to Buffer Overflow (CWE-680)

2021-09-01 cve@checkpoint.com

RCE Buffer Overflow Amazon Kindle Firmware

8.6

CVSS 3.1 · NVD

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Vulnerability Assessment

Weakness	CWE CWE-680 ASVS 5.0 V15 - Secure Coding and Architecture Integer-to-buffer conversion safety
Impact	CVSS score of 8.6 (HIGH). Attack characteristics: local attack vector, low complexity, no privileges required, user interaction required. Public proof-of-concept exploit code is available.
Exploit ScenarioDerived	Successful exploitation could compromise the high-severity affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 7.0% exploitation probability (EPSS)

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AnalysisAI

Amazon Kindle e-reader prior to and including version 5.13.4 contains an Integer Overflow that leads to a Heap-Based Buffer Overflow in function CJBig2Image::expand() and results in a memory. Rated high severity (CVSS 8.6), 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. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affects your stack

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Technical ContextAI · show details

This vulnerability is classified under CWE-680. Amazon Kindle e-reader prior to and including version 5.13.4 contains an Integer Overflow that leads to a Heap-Based Buffer Overflow in function CJBig2Image::expand() and results in a memory corruption that leads to code execution when parsing a crafted PDF book. Affected products include: Amazon Kindle Firmware. Version information: version 5.13.4.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 8.6 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

DescriptionNVD

Amazon Kindle e-reader prior to and including version 5.13.4 contains an Integer Overflow that leads to a Heap-Based Buffer Overflow in function CJBig2Image::expand() and results in a memory corruption that leads to code execution when parsing a crafted PDF book.

Threat Intelligence Overview

EPSS Score

7.0%

Top 7% 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 HIGH

CISA KEV No

Public POC Yes

EPSS 7.0%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

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: +7

CVSS: +43

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.

Remote Code Execution CRITICAL

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.