CVE-2017-5997 in SAP
Summary
by MITRE
The SAP Message Server HTTP daemon in SAP KERNEL 7.21-7.49 allows remote attackers to cause a denial of service (memory consumption and process crash) via multiple msgserver/group?group= requests with a crafted size of the group parameter, aka SAP Security Note 2358972.
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Analysis
by VulDB Data Team • 08/15/2020
The vulnerability identified as CVE-2017-5997 resides within the SAP Message Server HTTP daemon component of SAP KERNEL versions 7.21 through 7.49. This flaw represents a critical denial of service condition that can be exploited remotely by attackers to consume excessive system resources and ultimately cause process crashes. The SAP Message Server serves as a central communication hub for SAP systems, managing message routing and process coordination across distributed components. When compromised through this vulnerability, the daemon becomes susceptible to memory exhaustion attacks that can severely impact business continuity and system availability. The vulnerability specifically targets the HTTP daemon's handling of group parameter values in msgserver/group?group= requests, making it particularly dangerous in environments where the Message Server is exposed to untrusted networks or external traffic.
The technical exploitation mechanism involves sending multiple crafted HTTP requests to the vulnerable Message Server daemon with specially constructed group parameter values. These requests cause the daemon to allocate excessive memory resources in an uncontrolled manner, leading to gradual memory consumption until system resources are exhausted. The vulnerability stems from inadequate input validation and memory management within the HTTP daemon's request processing logic. The attacker does not require authentication to exploit this weakness, making it particularly dangerous as it can be leveraged by anyone who can reach the affected system. The specific nature of the flaw allows for a form of resource exhaustion attack that can be sustained over time, potentially leading to complete system crashes or unavailability of critical SAP services. This vulnerability directly maps to CWE-400, which addresses unchecked resource consumption, and represents a classic example of a denial of service attack that targets memory management.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire SAP landscapes that depend on message server functionality. Organizations utilizing SAP systems in mission-critical environments face significant risk of business interruption when this vulnerability is exploited, as the Message Server is fundamental to SAP system coordination and communication. The memory consumption pattern can be particularly insidious as it may not immediately manifest as system crashes but rather as gradual performance degradation that can go unnoticed until complete system failure occurs. This vulnerability affects a substantial portion of SAP installations since the affected kernel versions were widely deployed across enterprise environments. The impact is amplified in high-traffic environments where the Message Server handles numerous concurrent requests, making the system more susceptible to rapid resource exhaustion. Attackers can leverage this vulnerability to create sustained denial of service conditions that can persist until manual intervention or system restart occurs, potentially causing cascading failures throughout interconnected SAP applications and services.
Organizations should implement immediate mitigations including applying the relevant SAP security note 2358972 which provides specific patches and workarounds for this vulnerability. Network segmentation and access controls should be enforced to limit exposure of the Message Server to untrusted networks, implementing firewalls that restrict access to the affected ports and services. Monitoring systems should be enhanced to detect unusual memory consumption patterns and abnormal request volumes that may indicate exploitation attempts. The implementation of rate limiting mechanisms on HTTP daemon endpoints can help prevent rapid exploitation through multiple concurrent requests. Additionally, organizations should conduct comprehensive vulnerability assessments to identify all instances of affected SAP KERNEL versions and prioritize remediation efforts based on risk exposure and business criticality. The mitigation strategy should also include regular security updates and patch management processes to ensure continued protection against similar vulnerabilities. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving resource exhaustion and denial of service, representing a common attack pattern that adversaries use to disrupt system availability and compromise operational resilience in enterprise environments.