CVE-2018-3841 in Renderman IT Display Service
Summary
by MITRE
A denial-of-service vulnerability exists in the Pixar Renderman IT Display Service 21.6 (0x69). The vulnerability is present in the parsing of a network packet without proper validation of the packet. The data read-in is not validated, and its use can lead to a null pointer dereference. The IT application is opened by a user and then listens for a connection on port 4001. An attacker can deliver an attack once the application has been opened.
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Analysis
by VulDB Data Team • 02/22/2020
The CVE-2018-3841 vulnerability represents a critical denial-of-service weakness in Pixar Renderman's IT Display Service version 21.6, operating under the identifier 0x69. This flaw resides within the network packet processing functionality of the application, specifically in how it handles incoming data without adequate validation mechanisms. The vulnerability manifests when the application parses network packets that are transmitted to it through the IT Display Service interface, creating a scenario where unvalidated data can cause system instability. The affected service operates by opening a listening port on 4001, which remains accessible once the application has been launched by a user, making it susceptible to remote exploitation.
The technical root cause of this vulnerability stems from improper input validation during network packet processing, which directly maps to CWE-129, Input Validation, and CWE-476, NULL Pointer Dereference. When the IT Display Service receives a malformed packet, it fails to validate the incoming data structure before attempting to process it, leading to a situation where a null pointer dereference occurs during execution. This type of vulnerability allows an attacker to manipulate the application's memory handling behavior through carefully crafted network traffic, effectively causing the service to crash or become unresponsive. The attack vector is particularly concerning because it requires no authentication or elevated privileges, as the service is already running and listening on the network port.
The operational impact of this vulnerability extends beyond simple service disruption, potentially affecting creative workflows in professional animation and visual effects environments where Pixar Renderman is deployed. When exploited, the vulnerability can cause the IT Display Service to terminate unexpectedly, forcing users to restart the application and potentially interrupting ongoing rendering processes or collaborative work sessions. The vulnerability's accessibility through network connections means that any system running the affected service is at risk, particularly in enterprise environments where multiple users might be accessing shared rendering resources. This represents a significant concern for organizations that rely on consistent rendering pipeline availability and could lead to productivity losses or project delays.
Mitigation strategies for CVE-2018-3841 should prioritize immediate patch application from Pixar, as this vulnerability affects a core component of their rendering software suite. Organizations should implement network segmentation to restrict access to port 4001, particularly when the service is not actively needed, effectively reducing the attack surface. Network access control lists and firewall rules can be configured to limit connections to the specific IP addresses or ranges that require access to the IT Display Service. Additionally, monitoring for unusual network traffic patterns on port 4001 can help detect potential exploitation attempts. From an operational standpoint, regular security assessments of rendering environments and maintaining updated software versions are essential practices that align with industry standards for protecting against similar vulnerabilities. The ATT&CK framework categorizes this type of vulnerability under T1499.004, Endpoint Denial of Service, highlighting the importance of protecting service availability in enterprise security postures.