Tag Archives: Deserialization

Safer deserialization in Spring Security OAuth2

The Java standard library provides the ObjectInputStream class which offers a convenient way for deserializing Java objects. Unfortunately, this way is not safe by default. Using this class may open the doors for Java deserialization attacks which in the worse case may result in arbitrary code execution.

I recently discovered that Spring Security OAuth2 library may be vulnerable to such an attack. Fortunately, there is one strong pre-requisite for a successful attack which may be difficult to meet for an adversary. Nevertheless, I thought it might be better to make the library a bit safer, and the project maintainers kindly accepted the contribution. Here are the details.

Safer deserialization in Spring Security OAuth 2.4.0
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Safer deserialization with new Jackson 2.10

New Jackson 2.10 was released on Sep 26th, 2019. Everyone who uses the library and also scans their applications for known vulnerabilities knows about the problem with endless CVEs that have been reporting against Jackson. Let’s try to understand what makes an application vulnerable and how the new version of Jackson can help to prevent deserialization vulnerabilities.

Safer deserialization with new Jackson 2.10
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