FasterXML jackson-databind ObjectMapper readValue Method Blacklist Bypass Code Execution Vulnerability

CVE Number = CVE-2018-7489

A vulnerability in FasterXML jackson-databind could allow an unauthenticated, remote attacker to bypass security restrictions and execute arbitrary code on a targeted system.

The vulnerability is due to improper validation of user-input handled by the readValue method of the ObjectMapper object used by the affected software. An attacker could exploit this vulnerability by sending malicious JSON input to the vulnerable method of a web application that uses c3p0 libraries in the application’s classpath. An exploit could allow the attacker to execute arbitrary code within the security context of the affected application.

FasterXML has confirmed the vulnerability and released software updates.

Analysis
  • To exploit this vulnerability, an attacker must send crafted JSON input to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.

    This vulnerability is resolved by blacklisting c3p0 classes used in web applications, which extends upon a previous deserialization issue covered by CVE-2017-7525. Cisco previously documented CVE-2017-7525 at the follow link: Alert 56117

Safeguards
  • Administrators are advised to apply the appropriate updates.

    Administrators are advised to allow only trusted users to have network access.

    Administrators can help protect affected systems from external attacks by using a solid firewall strategy.

    Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.

    Administrators are advised to monitor affected systems.

Vendor Announcements
  • FasterXML has released a security issue at the following link: Issue #1931
Fixed Software

Duncan Newell

Duncan is a technology professional with over 20 years experience of working in various IT roles. He also has a wide range of other skills in radio, electronics and telecommunications.

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