CVE-2026-76980 in Firewall Analyzer
Summary
by MITRE • 09/23/2026
ZohoCorp ManageEngine OpManager and Firewall Analyzer versions 12.8.709 and below were vulnerable to a Data Exposure vulnerability in the Firewall Analyzer syslog collector.
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Analysis
by VulDB Data Team • 09/23/2026
The identified security flaw resides within the syslog collection component of Zoho Corp's ManageEngine products, specifically affecting Firewalls Analyzer and OpManager versions 12.8.709 and earlier. This vulnerability constitutes an unauthorized data exposure incident where sensitive information accessible through the application is inadvertently disclosed to unauthenticated or improperly authorized users. The core technical deficiency lies in the handling of syslog messages by the collector service, which fails to enforce adequate access controls or input validation mechanisms when processing incoming log streams from network devices such as firewalls and routers. This architectural oversight allows an attacker who can reach the affected system over a network connection to exploit the misconfiguration within the logging subsystem.
From a technical perspective, the vulnerability is classified under CWE-200, which denotes Information Exposure, specifically falling into categories related to sensitive information disclosure in error messages or through improper access control mechanisms on API endpoints and data collection services. The syslog protocol itself is designed for log aggregation but often lacks built-in encryption or strong authentication by default, making it a frequent target for interception if the receiving service does not implement additional security layers such as TLS termination with client certificate verification or strict IP-based allowlisting at the application layer. In this specific instance, the flaw suggests that the syslog collector endpoint either accepts connections from any source without verifying identity or exposes internal diagnostic data and raw log contents to external parties who can query the collection interface directly.
The operational impact of this vulnerability is significant for organizations relying on these tools for security monitoring and network management. An attacker with access to the vulnerable service could potentially harvest sensitive configuration details, user activity logs, IP addresses, and other metadata contained within the syslog messages. This information serves as high-value intelligence for subsequent attack phases, enabling threat actors to map internal network topology, identify active users or administrative accounts, and understand security controls in place. Such exposure facilitates reconnaissance activities that align with MITRE ATT&CK technique T1078, Valid Accounts, if credentials are found within logs, or more broadly under Initial Access techniques like T1596, Search Open Technical Databases, by leveraging the exposed data to refine social engineering or targeted attacks against specific infrastructure components.
Furthermore, the presence of this vulnerability indicates a gap in the principle of least privilege and secure default configurations for enterprise management suites. The syslog collector is often configured with broad network accessibility to accommodate various logging sources, but without proper segmentation or authentication enforcement, it becomes an open door for data exfiltration. This risk is compounded by the fact that log files frequently contain plaintext passwords, session tokens, or internal IP schemes depending on how devices are configured to send logs. The exposure of such granular details can lead to a complete compromise of network integrity if not addressed promptly, as it provides adversaries with the contextual knowledge required to bypass perimeter defenses and move laterally within the environment.
To mitigate this risk, organizations must immediately upgrade ManageEngine OpManager and Firewall Analyzer to version 12.8.709 or any subsequent release where the vendor has patched the access control logic in the syslog collector. Until an update is applied, administrators should implement network-level controls such as firewall rules that restrict access to the syslog collection ports exclusively from trusted management subnets or specific log source IP addresses. Additionally, enabling TLS encryption for syslog transmission and configuring mutual authentication can prevent unauthorized parties from intercepting or injecting logs into the system. Regular auditing of application configurations against industry benchmarks like CIS Benchmarks is recommended to ensure that logging services are not exposed unnecessarily on public-facing interfaces and that all administrative access points require multi-factor authentication and strict role-based access control.