CVE-2025-3857
Infinite loop condition in Amazon.IonDotnet
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Infinite loop condition in Amazon.IonDotnet
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.
- Record
CVE-2025-3857- CVSS 4.0
- 8.7 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-835, CWE-502
- Updated
- 2026-11-02
EUVDEUVD-2025-12229
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.
- Record
EUVD-2025-12229- CVSS 4.0
- 8.7 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-gm2p-wf5c-w3pj
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 [email protected]. 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.
- Record
GHSA-gm2p-wf5c-w3pj- CVSS 4.0
- 8.7 High
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-502, CWE-835
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-3857- CVSS 4.0
- 8.7 High
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-502, CWE-835
- Updated
- 2026-11-02
OSV
Infinite loop condition in Amazon.IonDotnet
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.
- Record
CVE-2025-3857- CVSS 4.0
- 8.7 High
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 - Weakness
- CWE-502, CWE-835
- Updated
- 2026-11-02
OSVGHSA-gm2p-wf5c-w3pj
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 [email protected]. 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.
- Record
GHSA-gm2p-wf5c-w3pj- CVSS 4.0
- 8.7 High
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-502, CWE-835
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
Amazon.IonDotnetNuGet |
before 1.3.1 | 1.3.1 |
Amazon.IonDotnetNuGet |
before 1.3.1, plus listed versions 0.9.0-beta1.0.01.1.01.2.21.2.31.3.0 |
1.3.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-3857 is a high vulnerability (CVSS 8.7) in Amazon Ion Dotnet, published April 21, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 50th percentile. Fixed in Amazon.IonDotnet 1.3.1.
References
aws.amazon.com/security/security-bulletins/AWS-2025-009
github.com/amazon-ion/ion-dotnet/security/advisories/GHSA-gm2p-wf5c-w3pj
nvd.nist.gov/vuln/detail/CVE-2025-3857