CVE-2020-36185

Q: What is the severity of CVE-2020-36185?

CVE-2020-36185 has a CVSS score of 8.1 (HIGH). This vulnerability in FasterXML jackson-databind allows remote code execution through deserialization of untrusted data. Attackers can exploit the interaction between serialization gadgets and typing to execute arbitrary code on affected systems. Any application using vulnerable versions of jackson-databind with default or unsafe configurations is affected.

8.1 HIGH

Remote Code Execution Deserialization

📋 TL;DR

This vulnerability in FasterXML jackson-databind allows remote code execution through deserialization of untrusted data. Attackers can exploit the interaction between serialization gadgets and typing to execute arbitrary code on affected systems. Any application using vulnerable versions of jackson-databind with default or unsafe configurations is affected.

💻 Affected Systems

Products:

FasterXML jackson-databind
Applications using jackson-databind for JSON processing
Apache Tomcat with DBCP2

Versions: 2.x before 2.9.10.8

Operating Systems: All

Default Config Vulnerable: ⚠️ Yes

Notes: Vulnerability requires enabling default typing or polymorphic type handling. Applications using default or unsafe deserialization configurations are most vulnerable.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise, data theft, and lateral movement within the network.

🟠

Likely Case

Remote code execution allowing attackers to run arbitrary commands, install malware, or exfiltrate sensitive data.

🟢

If Mitigated

Limited impact if proper input validation and deserialization controls are implemented, potentially reduced to denial of service.

🌐 Internet-Facing: HIGH

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires sending specially crafted JSON payloads to vulnerable endpoints. Attack complexity is reduced when default typing is enabled.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 2.9.10.8 or later

Vendor Advisory: https://github.com/FasterXML/jackson-databind/issues/2998

Restart Required: Yes

Instructions:

1. Update jackson-databind dependency to version 2.9.10.8 or later. 2. Update Maven/Gradle dependencies accordingly. 3. Restart affected applications. 4. Verify the update by checking the version in use.

🔧 Temporary Workarounds

Disable default typing

all

Disable polymorphic type handling and default typing in Jackson ObjectMapper configuration

ObjectMapper mapper = new ObjectMapper();
mapper.activateDefaultTyping(null); // Disable default typing
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, true);

Block dangerous classes

all

Configure Jackson to block deserialization of dangerous gadget classes

SimpleModule module = new SimpleModule();
module.setDeserializerModifier(new BeanDeserializerModifier() {
  @Override
  public JsonDeserializer<?> modifyDeserializer(...) {
    // Add class blocking logic
  }
});

🧯 If You Can't Patch

Implement strict input validation and sanitization for all JSON inputs
Use network segmentation to isolate vulnerable systems and limit attack surface

🔍 How to Verify

Check if Vulnerable:

Check pom.xml or build.gradle for jackson-databind version. Run: mvn dependency:tree | grep jackson-databind or gradle dependencies | grep jackson-databind

Check Version:

java -cp "path/to/jackson-databind.jar" com.fasterxml.jackson.databind.ObjectMapper | grep version

Verify Fix Applied:

Verify the version is 2.9.10.8 or higher. Check application logs for successful startup with updated version.

📡 Detection & Monitoring

Log Indicators:

Unusual deserialization errors
Stack traces containing org.apache.tomcat.dbcp
Unexpected class loading attempts

Network Indicators:

Large or malformed JSON payloads to API endpoints
Requests containing serialized object patterns

SIEM Query:

source="application.logs" AND ("jackson" OR "deserialization") AND (error OR exception)

📊 Metadata

CVE ID: CVE-2020-36185

CVSS v3 Score: 8.1 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-502

Published: January 6, 2021

Last Updated: November 21, 2024

🔗 References

https://cowtowncoder.medium.com/on-jackson-cves-dont-panic-here-is-what-you-need-to-know-54cd0d6e8062 Exploit,Technical Description,Third Party Advisory
https://github.com/FasterXML/jackson-databind/issues/2998 Issue Tracking,Patch,Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/04/msg00025.html Mailing List,Third Party Advisory
https://security.netapp.com/advisory/ntap-20210205-0005/ Third Party Advisory
https://www.oracle.com//security-alerts/cpujul2021.html Patch,Third Party Advisory
https://www.oracle.com/security-alerts/cpuApr2021.html Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Patch,Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.html Patch,Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html Third Party Advisory
https://www.oracle.com/security-alerts/cpuoct2021.html Patch,Third Party Advisory
https://cowtowncoder.medium.com/on-jackson-cves-dont-panic-here-is-what-you-need-to-know-54cd0d6e8062 Exploit,Technical Description,Third Party Advisory
https://github.com/FasterXML/jackson-databind/issues/2998 Issue Tracking,Patch,Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/04/msg00025.html Mailing List,Third Party Advisory
https://security.netapp.com/advisory/ntap-20210205-0005/ Third Party Advisory
https://www.oracle.com//security-alerts/cpujul2021.html Patch,Third Party Advisory
https://www.oracle.com/security-alerts/cpuApr2021.html Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Patch,Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.html Patch,Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html Third Party Advisory
https://www.oracle.com/security-alerts/cpuoct2021.html Patch,Third Party Advisory

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Agile Plm by Oracle

Application Testing Suite by Oracle

Autovue For Agile Product Lifecycle Management by Oracle

Banking Corporate Lending Process Management by Oracle

Banking Corporate Lending Process Management by Oracle

Banking Corporate Lending Process Management by Oracle

Banking Credit Facilities Process Management by Oracle

Banking Credit Facilities Process Management by Oracle

Banking Credit Facilities Process Management by Oracle

Banking Extensibility Workbench by Oracle

Banking Extensibility Workbench by Oracle

Banking Extensibility Workbench by Oracle

Banking Supply Chain Finance by Oracle

Banking Supply Chain Finance by Oracle

Banking Supply Chain Finance by Oracle

Banking Treasury Management by Oracle

Banking Virtual Account Management by Oracle

Banking Virtual Account Management by Oracle

Banking Virtual Account Management by Oracle

Blockchain Platform by Oracle

Cloud Backup by Netapp

Commerce Platform by Oracle

Commerce Platform by Oracle

Communications Billing And Revenue Management by Oracle

Communications Billing And Revenue Management by Oracle

Communications Cloud Native Core Policy by Oracle

Communications Cloud Native Core Unified Data Repository by Oracle

Communications Convergent Charging Controller by Oracle

Communications Diameter Signaling Route by Oracle

Communications Element Manager by Oracle

Communications Evolved Communications Application Server by Oracle

Communications Instant Messaging Server by Oracle

Communications Network Charging And Control by Oracle

Communications Offline Mediation Controller by Oracle

Communications Policy Management by Oracle

Communications Pricing Design Center by Oracle

Communications Services Gatekeeper by Oracle

Communications Session Report Manager by Oracle

Communications Session Route Manager by Oracle

Communications Unified Inventory Management by Oracle

Data Integrator by Oracle

Debian Linux by Debian

Documaker by Oracle

Documaker by Oracle

Documaker by Oracle

Goldengate Application Adapters by Oracle

Insurance Policy Administration by Oracle

Insurance Policy Administration by Oracle

Insurance Rules Palette by Oracle

Insurance Rules Palette by Oracle

Jackson Databind by Fasterxml

Jackson Databind by Fasterxml

Jd Edwards Enterpriseone Orchestrator by Oracle

Jd Edwards Enterpriseone Tools by Oracle

Primavera Gateway by Oracle

Primavera Gateway by Oracle

Primavera Gateway by Oracle

Primavera Gateway by Oracle

Primavera Unifier by Oracle

Primavera Unifier by Oracle

Primavera Unifier by Oracle

Primavera Unifier by Oracle

Primavera Unifier by Oracle

Retail Customer Management And Segmentation Foundation by Oracle

Retail Merchandising System by Oracle

Retail Service Backbone by Oracle

Retail Service Backbone by Oracle

Retail Service Backbone by Oracle

Retail Xstore Point Of Service by Oracle

Retail Xstore Point Of Service by Oracle

Retail Xstore Point Of Service by Oracle

Retail Xstore Point Of Service by Oracle

Service Level Manager by Netapp

Webcenter Portal by Oracle

Webcenter Portal by Oracle

⚠️ Risk & Real-World Impact

Worst Case