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The vulnerability in Amazon.IonDotnet arises from improper handling of a specific error condition during the parsing of Ion text data. When the library encounters a malformed, non-conforming Ion text input, it triggers a parser error. However, the control flow for handling this specific error is flawed. Instead of safely aborting the parsing process and throwing an exception, the parser enters an inconsistent state, causing it to repeatedly attempt and fail to process the same invalid token. This creates a tight, infinite loop that consumes 100% of a single CPU core, leading to a complete denial of service for the application using the library. The attack requires minimal input size, as a small crafted string is sufficient to trigger the persistent loop, making it efficient for an attacker to exhaust server resources.
Platform: .NET
Version: <1.3.2
Vulnerability: Infinite Loop
Severity: Critical
date: 2025-08-20
Prediction: 2025-08-27
What Undercode Say:
`dotnet list package`
`IonReaderText.ParseNext()`
`while (state == Invalid)`
How Exploit:
Crafted Ion text
Parser error trigger
CPU exhaustion loop
Protection from this CVE
Upgrade to v1.3.2
Restrict input sources
Use binary Ion
Impact:
Application Hang
Resource Exhaustion
Denial of Service
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Sources:
Reported By: github.com
Extra Source Hub:
Undercode
