External risk intelligence

Jackson Databind Default Typing Vulnerability Allows Data Exfiltration.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2018-11307

The vulnerability exists in jackson-databind, a widely used software library for JSON processing. While it is not a standalone internet-facing service, it is frequently integrated into web applications and APIs that process external input. The potential for reachability depends entirely on how the library is implemented by the host application, making public exposure possible but context-dependent.

Deserialization

Fasterxml Jackson Databind

2.0.0 to before 2.6.7.32.7.0 to before 2.7.9.42.8.0 to before 2.8.11.22.9.0 to before 2.9.63.114.112.1.0.2.010.0.1.2.0before 11.2.0.3.2312.2.0.1.0 to before 12.2.0.1.1913.9.4.0....

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

An issue was discovered in a widely used software library for JSON processing, which, when combined with another specific programming technique, could lead to the unauthorized access and potential exfiltration of sensitive information. This vulnerability affects various applications and systems that rely on this library for data handling.

A software library flaw allows unauthorized access.
Critical for systems processing sensitive data.
Confirm relevance and assess exposure.

Attack Path

How an attacker could exploit the issue

An attacker can exploit this vulnerability by sending specially crafted data over the network to a system that uses a vulnerable version of the Jackson library. If the system processes this data with default type handling enabled and a specific gadget class is available, the attacker could potentially exfiltrate sensitive information.

Network access required.
Triggered by malicious data processing.
Allows sensitive data exfiltration.

Live Threat

Current exploitation, exposure, and threat context

When supported by the advisory, the use of Jackson's default typing with a specific gadget class could allow for the exfiltration of content from systems processing JSON data.

System data or sensitive information could be affected.
Unauthenticated network access may lead to exposure.
Unauthorized content exfiltration is a potential consequence.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in `jackson-databind` could allow for sensitive data exfiltration if default typing is enabled and specific gadget classes from iBatis are present. In a real-world scenario, application owners, platform teams, and potentially vendor management teams are likely responsible for addressing this. The first practical step is to identify all instances of the affected `jackson-databind` library, confirm exposure, and then prioritize remediation based on criticality and reachability.

Application owners should own the issue.
Verify library usage and default typing.
Plan remediation during maintenance windows.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is jackson-databind?

Jackson-databind is a popular Java library used by developers to process and map JSON data. It acts as a bridge, converting JSON input into Java objects that applications can easily manipulate. Because of its efficiency and flexibility, it is embedded in numerous enterprise platforms—including those from Red Hat and Oracle—to handle data serialization and deserialization across web applications.

What does CVE-2018-11307 mean?

This vulnerability is classified as Improper Neutralization of Input During Web Page Generation or Data Transformation (CWE-502). It occurs when the library is configured to use 'default typing,' which allows it to instantiate arbitrary classes. If an attacker provides malicious JSON that triggers a specific 'gadget' class—in this case from iBatis—they can force the application to perform unauthorized actions, potentially leading to content exfiltration.

How is this vulnerability triggered?

The issue is triggered when an application receives and processes specially crafted JSON input from a network source while default typing is enabled. It is important to note that the presence of the library alone is not enough; the vulnerability specifically requires the combination of enabled default typing and the presence of the iBatis gadget class within the application's environment to successfully execute.

Is my system at risk?

Halo Surface Signal notes that while jackson-databind is not a standalone service, it is often embedded in APIs and web applications that process external data. Your risk depends on whether your specific application uses vulnerable library versions and has enabled default typing. If your application processes untrusted JSON input from the internet, it is more likely to be reachable by an attacker.

What should I do to secure my environment?

Your first step is to inventory your systems to locate all instances of the affected library versions. Consult your vendors—such as Red Hat or Oracle—to check for recommended updates or patches specific to your software stack. If immediate patching is not possible, work with your development team to verify if default typing is strictly necessary or if it can be disabled to mitigate the risk.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.