CVE-2025-3857 Infinite loop condition in Amazon.IonDotnet
An infinite loop in Amazon.IonDotnet's binary reader allows attackers to cause denial of service via malformed data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-3857?
CVE-2025-3857 is a high-severity denial of service vulnerability in Amazon Ion Dotnet, published on 21 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2025-3857?
2 open source packages ship an affected version, including Amazon.IonDotnet.
| Package | Affected | Fixed in |
|---|---|---|
Amazon.IonDotnet NuGet | All versions | 1.3.1 |
Amazon.IonDotnet NuGet | All versions | 1.3.1 |
How do I fix CVE-2025-3857?
Upgrade Amazon.IonDotnet to 1.3.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-3857 being exploited?
There is no known exploitation of CVE-2025-3857 in the wild and no public exploit code.
Sources
Also known as GHSA-gm2p-wf5c-w3pj.