CVE-2018-20032 in FlexNet Publisher
Summary
by MITRE
A Denial of Service vulnerability related to message decoding in lmgrd and vendor daemon components of FlexNet Publisher version 11.16.1.0 and earlier allows a remote attacker to send a combination of messages to lmgrd or the vendor daemon, causing the heartbeat between lmgrd and the vendor daemon to stop, and the vendor daemon to shut down.
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Analysis
by VulDB Data Team • 08/04/2023
This vulnerability resides within the FlexNet Publisher licensing system, specifically affecting lmgrd and vendor daemon components in versions 11.16.1.0 and earlier. The flaw represents a critical denial of service condition that can be exploited remotely through carefully crafted message sequences. The vulnerability manifests when an attacker sends a specific combination of messages to either the lmgrd process or the vendor daemon, which triggers a breakdown in the heartbeat communication mechanism that maintains system synchronization between these critical components. This disruption ultimately leads to the vendor daemon shutting down completely, effectively rendering the licensing system non-functional and disrupting legitimate software usage.
The technical root cause of this vulnerability stems from inadequate input validation and message handling within the licensing daemon processes. When the lmgrd and vendor daemon components receive malformed or specially crafted messages, the system fails to properly decode and process these inputs, leading to an unexpected termination of the heartbeat mechanism. This represents a classic example of insufficient error handling and lack of proper message validation, which can be categorized under CWE-248 as an "Uncaught Exception" and CWE-707 as "Improper Neutralization of Input During Web Page Generation." The vulnerability demonstrates poor defensive programming practices where the system does not adequately protect against malformed inputs that could cause process termination.
The operational impact of this vulnerability extends beyond simple service disruption, as it fundamentally compromises the availability of the licensing infrastructure. Organizations relying on FlexNet Publisher for software licensing may experience complete licensing failures, preventing legitimate users from accessing protected software applications. The remote exploitability means that attackers can initiate this attack from anywhere on the network without requiring local system access or authentication credentials, making it particularly dangerous in enterprise environments where licensing servers may be exposed to external networks. This vulnerability directly maps to the ATT&CK technique T1499.004 for "Endpoint Denial of Service" and represents a significant risk to business continuity and software deployment operations.
Mitigation strategies should focus on immediate patching of affected systems to version 11.16.2.0 or later, which contains the necessary fixes for the message decoding vulnerabilities. Network segmentation should be implemented to limit access to licensing servers, particularly restricting direct network access to the lmgrd and vendor daemon ports. Additionally, implementing network monitoring to detect unusual message patterns and heartbeat disruptions can provide early warning of potential exploitation attempts. Organizations should also consider implementing intrusion detection systems that can identify and alert on known exploit patterns targeting FlexNet Publisher components. The vulnerability underscores the importance of maintaining current software versions and implementing proper input validation mechanisms in critical infrastructure components, aligning with security best practices outlined in the NIST Cybersecurity Framework and ISO 27001 standards for information security management.