What is CVE-2025-3857?

CVE-2025-3857 is a high-severity vulnerability in Amazon Ion Dotnet, classified under Deserialization of Untrusted Data. CVSS score: 7.5/10. Published 2025-04-21.

How severe is CVE-2025-3857?

High severity. CVSS v3 base score is 7.5 out of 10.

Deserialization in Amazon Ion Dotnet

CVE-2025-3857

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.

Vulnerability class: Insecure Deserialization

EPSS: 0.006 (44.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Amazon Ion Dotnet — versions 0

Weakness classification (CWE)

References

ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (third-party-advisory)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (patch)

Frequently asked questions

What is CVE-2025-3857?: CVE-2025-3857 is a high-severity vulnerability in Amazon Ion Dotnet, classified under Deserialization of Untrusted Data. CVSS score: 7.5/10. Published 2025-04-21.
How severe is CVE-2025-3857?: High severity. CVSS v3 base score is 7.5 out of 10.