CVE-2025-11573: Denial of Service issue in Amazon.IonDotnet
Summary Amazon.IonDotnet is a library for the Dotnet language that is used to read and write Amazon Ion data. An issue exists where, under certain circumstances, the library could an infinite loop, resulting in denial of service. As of August 20, 2025, this library has been deprecated and will not receive further updates.
Impact An infinite loop issue in Amazon.IonDotnet library versions <v1.3.2 may allow a threat actor to cause a denial of service through a specially crafted text input. This invalid input triggered an error condition in the parser that was handled improperly, resulting in an infinite loop.
Impacted versions: <1.3.2
Patches This issue has been addressed in Amazon.IonDotnet version 1.3.2. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Workarounds Only accept data from trusted sources, written using a supported Ion library.
References If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.
Other sources
An infinite loop issue in Amazon.IonDotnet library versions <v1.3.2 may allow a threat actor to cause a denial of service through a specially crafted text input.
To mitigate this issue, users should upgrade to version v1.3.2. As of August 20, 2025, this library has been deprecated and will not receive further updates.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
nuget/Amazon.IonDotnetto a version that resolves this vulnerability.Fixed in 1.3.2 - Upgrade
Upgrade
Amazon.IonDotnetto a version that resolves this vulnerability.Fixed in 1.3.2 - Compensating control
Only accept data from trusted sources, written using a supported Ion library.
Event History
Frequently Asked Questions
What is the severity of CVE-2025-11573?
CVE-2025-11573 has a medium severity due to its potential to cause a denial of service.
How do I fix CVE-2025-11573?
To fix CVE-2025-11573, upgrade to Amazon IonDotnet library version 1.3.2 or later.
What products are affected by CVE-2025-11573?
CVE-2025-11573 affects Amazon IonDotnet library versions below 1.3.2.
What kind of threat does CVE-2025-11573 pose?
CVE-2025-11573 poses a threat of denial of service (DoS) through an infinite loop caused by specially crafted text input.
Is CVE-2025-11573 still supported after the fix?
As of August 20, 2025, Amazon IonDotnet library has been deprecated, so no further updates will be provided beyond version 1.3.2.