Infinite loop condition in Amazon.IonDotnet
Summary
Amazon.IonDotnet (ion-dotnet) is a .NET library with an implementation of the Ion data serialization format.
An issue exists in Amazon.IonDotnet and the RawBinaryReader class where, under certain conditions, an actor could trigger an infinite loop condition.
Impact
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.
Impacted versions: <=1.3.0
Patches
This issue has been addressed in Amazon.IonDotnet version 1.3.1. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Workarounds
There are no workarounds. Upgrade to version 1.3.1.
References
If you have any questions or comments about this advisory, contact AWS/Amazon Security via our vulnerability reporting page or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.
Credit
We would like to thank Josh Coleman from Symbotic for collaborating on this issue through the coordinated vulnerability disclosure process.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| .NET (NuGet) | Amazon.IonDotnet | < 1.3.1 | 1.3.1 |
References
- https://github.com/amazon-ion/ion-dotnet/security/advisories/GHSA-gm2p-wf5c-w3pj
- https://nvd.nist.gov/vuln/detail/CVE-2025-3857
- https://github.com/amazon-ion/ion-dotnet/commit/34a4f5215eceac1bb7bf434c4f2310d64d1b703b
- https://aws.amazon.com/security/security-bulletins/AWS-2025-009
- https://github.com/amazon-ion/ion-dotnet
- https://github.com/amazon-ion/ion-dotnet/releases/tag/v1.3.1
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-502, CWE-835- Platform
- .NET (NuGet)
- Package
Amazon.IonDotnet- Disclosed
- 21.04.2025
- Updated
- 11.10.2026 11:23
Sources and licenses
OSV / GitHub Advisory Database - GHSA-gm2p-wf5c-w3pj - CC BY 4.0
Vulnerability history: Amazon.IonDotnet
All published vulnerabilities of this package (.NET (NuGet)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 04.2025 10.2025
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 2
Disclosures per year
- 2025: 2
- 2026: 0
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Infinite loop condition in Amazon.IonDotnet this entry
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