# CVE-2025-3857

## Summary

- **CVE ID:** CVE-2025-3857
- **Severity:** HIGH
- **CVSS Score:** 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-835, CWE-502
- **Published:** Apr 21, 2025
- **Last Modified:** Mar 12, 2026

## Description

When reading binary Ion data through Amazon.IonDotnet using the RawBinaryReader class, Amazon.IonDotnet does not check the number of bytes read from the underlying stream while deserializing the binary format. If the Ion data is malformed or truncated, this triggers an infinite loop condition that could potentially result in a denial of service. Users should upgrade to Amazon.IonDotnet version 1.3.1 and ensure any forked or derivative code is patched to incorporate the new fixes.

## Affected Products

- Amazon — Amazon Ion Dotnet (0)

## References

- [CNA](https://aws.amazon.com/security/security-bulletins/AWS-2025-009/)
- [CNA](https://github.com/amazon-ion/ion-dotnet/security/advisories/GHSA-gm2p-wf5c-w3pj)
- [CNA](https://github.com/amazon-ion/ion-dotnet/releases/tag/v1.3.1)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.59%
- **EPSS Percentile:** 46.1

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._