CVE-2018-1086 in PCS
Summary
by MITRE
pcs before versions 0.9.164 and 0.10 is vulnerable to a debug parameter removal bypass. REST interface of the pcsd service did not properly remove the pcs debug argument from the /run_pcs query, possibly disclosing sensitive information. A remote attacker with a valid token could use this flaw to elevate their privilege.
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Analysis
by VulDB Data Team • 02/28/2023
The vulnerability identified as CVE-2018-1086 affects the pcs (Pacemaker Configuration System) software versions prior to 0.9.164 and 0.10, specifically targeting the pcsd service REST interface. This security flaw represents a critical information disclosure issue that arises from improper handling of debug parameters within the system's query processing mechanism. The vulnerability manifests in the /run_pcs endpoint where the debug argument fails to be properly sanitized or removed from the query parameters, creating a potential attack vector for malicious actors.
The technical implementation of this vulnerability stems from inadequate input validation and parameter sanitization within the pcsd service architecture. When legitimate users submit queries through the REST interface using valid authentication tokens, the system processes these requests but fails to strip debug parameters from the query string before further processing. This oversight allows attackers to inject or manipulate debug arguments that should normally be restricted or removed during normal operation. The flaw operates at the application layer and specifically impacts the service's query parameter handling logic, creating a scenario where sensitive operational information could be inadvertently exposed through the debug parameter mechanism.
From an operational perspective, this vulnerability creates significant risk for systems utilizing the pcs configuration management framework. A remote attacker who has obtained a valid authentication token can exploit this weakness to potentially elevate their privileges and gain access to information that should remain confidential. The privilege escalation capability arises because the debug parameter removal bypass can be leveraged to manipulate system behavior or extract sensitive data that would normally be restricted. This vulnerability particularly affects high-availability cluster configurations where pcs is commonly deployed, potentially compromising the integrity and confidentiality of cluster management operations.
The security implications of CVE-2018-1086 align with CWE-200 (Information Disclosure) and CWE-284 (Improper Access Control) classifications, representing a combination of information exposure and privilege escalation risks. According to ATT&CK framework categorization, this vulnerability maps to T1078 (Valid Accounts) for the initial access vector and T1548.001 (Abuse Elevation Control Mechanism) for privilege escalation techniques. Organizations using affected versions of pcs should implement immediate mitigations including updating to patched versions, implementing additional access controls, and monitoring for suspicious query patterns that might indicate exploitation attempts.
Mitigation strategies for this vulnerability include upgrading to pcs versions 0.9.164 or 0.10 and later, which contain the necessary parameter sanitization fixes. System administrators should also implement network-level controls to restrict access to the pcsd REST interface, particularly limiting exposure to trusted networks only. Additional defensive measures include implementing comprehensive logging of all pcsd REST interface queries, monitoring for unusual parameter patterns, and conducting regular security assessments of cluster management systems. The vulnerability demonstrates the importance of proper input validation and parameter handling in service interfaces, particularly those handling privileged operations within high-availability environments where compromise could lead to widespread system disruption.