Deserialization injections occur when applications deserialize wholly or partially untrusted data without verification.
What is the potential impact?
In the context of a web application performing unsafe deserialization:
After detecting the injection vector, attackers inject a
carefully-crafted payload into the application.
Below are some real-world scenarios that illustrate some impacts of an attacker exploiting the vulnerability.
Application-specific attacks
In this scenario, the attackers succeed in injecting an object of the expected class, but with malicious properties that affect the object’s
behavior.
If the application relies on the properties of the deserialized object, attackers can modify the data structure or content to escalate privileges
or perform unwanted actions.
In the context of an e-commerce application, this could be changing the number of products or prices.
Full application compromise
In the worst-case scenario, the attackers succeed in injecting an object of a completely different class than expected, triggering code
execution.
Depending on the attacker, code execution can be used with different intentions:
- Download the internal server’s data, most likely to sell it.
- Modify data, install malware, for instance, malware that mines cryptocurrencies.
- Stop services or exhaust resources, for instance, with fork bombs.
This threat is particularly insidious if the attacked organization does not maintain a Disaster Recovery Plan (DRP).
Root privilege escalation and pivot
In this scenario, the attacker can do everything described in the previous section. The difference is that the attacker additionally manages to
elevate his privileges as an administrator and attack other servers.
Here, the impact depends on how much the target company focuses on its Defense In Depth. For example, the entire infrastructure can be compromised
through a combination of unsafe deserialization and misconfiguration:
- Docker or Kubernetes clusters
- cloud services
- network firewalls and routing
- OS access control
