CVE-2003-1518 in Winsyslog
Summary
by MITRE
Adiscon WinSyslog 4.21 SP1 allows remote attackers to cause a denial of service (CPU consumption) via a long syslog message.
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Analysis
by VulDB Data Team • 02/05/2025
The vulnerability identified as CVE-2003-1518 affects Adiscon WinSyslog version 4.21 SP1, representing a significant security flaw that impacts system availability through resource exhaustion. This issue manifests when remote attackers exploit a weakness in the syslog message processing mechanism, specifically targeting the system's ability to handle extended input data. The flaw resides in how the software processes incoming syslog messages, creating a condition where excessively long messages can trigger abnormal CPU consumption patterns that ultimately lead to system instability and denial of service conditions.
The technical implementation of this vulnerability stems from inadequate input validation and buffer management within the WinSyslog application's message handling routines. When a malicious actor sends a syslog message that exceeds normal processing limits, the system fails to properly truncate or reject such oversized inputs, instead attempting to process the entire message in a manner that consumes disproportionate computational resources. This behavior creates a resource exhaustion scenario where the CPU utilization spikes dramatically, effectively preventing legitimate system operations from functioning normally. The vulnerability operates at the application layer and can be exploited remotely without requiring authentication, making it particularly dangerous in networked environments where syslog services are commonly exposed.
From an operational impact perspective, this vulnerability presents a substantial risk to system availability and network reliability. Organizations relying on WinSyslog for centralized logging and monitoring may experience complete service outages when subjected to this attack vector. The sustained high CPU consumption can affect not only the syslog server itself but also adjacent systems that depend on its functionality for security monitoring, compliance reporting, and operational logging. Network administrators may observe degraded performance, system timeouts, and complete service unavailability that can persist until the affected system is manually restarted or the malicious input is filtered. The vulnerability's remote exploitability means that attackers can target these systems from outside the network perimeter, potentially amplifying the impact across multiple organizational domains that rely on syslog infrastructure.
Mitigation strategies for CVE-2003-1518 should focus on immediate protective measures and long-term architectural improvements. Organizations should implement input length restrictions and message size limits at the syslog server level to prevent oversized messages from being processed. Network-level filtering using firewalls and intrusion detection systems can help block suspicious syslog traffic patterns and limit the attack surface. Regular updates and patches should be applied to ensure that newer versions of WinSyslog incorporate proper input validation and resource management controls. The implementation of rate limiting mechanisms and message queuing systems can help absorb abnormal traffic patterns while maintaining system stability. Additionally, monitoring and alerting systems should be configured to detect unusual CPU utilization patterns that may indicate exploitation attempts. This vulnerability aligns with CWE-770, which addresses resource exhaustion issues, and represents a classic example of how improper input handling can lead to denial of service conditions, making it relevant to ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also consider implementing redundant logging systems and failover mechanisms to maintain operational continuity during potential exploitation attempts.