CVE-2009-1887 in Red Hat
Summary
by MITRE
agent/snmp_agent.c in snmpd in net-snmp 5.0.9 in Red Hat Enterprise Linux (RHEL) 3 allows remote attackers to cause a denial of service (daemon crash) via a crafted SNMP GETBULK request that triggers a divide-by-zero error. NOTE: this vulnerability exists because of an incorrect fix for CVE-2008-4309.
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Analysis
by VulDB Data Team • 04/09/2025
The vulnerability described in CVE-2009-1887 represents a critical denial of service weakness in the Simple Network Management Protocol daemon implementation within Red Hat Enterprise Linux 3. This issue affects the net-snmp 5.0.9 package where the snmpd service processes SNMP GETBULK requests through the agent/snmp_agent.c component. The vulnerability arises from a flawed attempt to address a previous security flaw, specifically CVE-2008-4309, which demonstrates how security patches can inadvertently introduce new weaknesses when not thoroughly tested or analyzed in the context of existing code behavior.
The technical root cause of this vulnerability stems from a divide-by-zero error that occurs when processing specially crafted SNMP GETBULK requests. When an attacker sends a malformed request that triggers this condition, the snmpd daemon experiences a critical failure leading to an immediate crash and subsequent denial of service. This type of error falls under CWE-369, which specifically addresses the divide by zero vulnerability pattern where a program attempts to divide a value by zero, causing system instability and potential service interruption. The vulnerability is particularly concerning because it operates at the protocol level, allowing remote attackers to exploit the service without requiring authentication or local access privileges.
The operational impact of this vulnerability extends beyond simple service disruption as it affects the availability of network management services that organizations depend upon for monitoring and maintaining their infrastructure. When the snmpd daemon crashes, network administrators lose visibility into their managed devices through SNMP protocols, potentially leading to extended downtime while services are restored and the system is brought back online. This vulnerability particularly affects enterprise environments where SNMP is extensively used for network monitoring, performance tracking, and system administration tasks. The fact that this vulnerability exists due to an incorrect fix for CVE-2008-4309 demonstrates a pattern of security remediation failures that can create cascading issues in software maintenance and patch management processes.
Organizations should implement immediate mitigations including applying the official patches provided by Red Hat that properly address both the original vulnerability and the regression introduced in the flawed fix. Network segmentation and access controls should be implemented to limit exposure of SNMP services to trusted networks only, while monitoring systems should be configured to detect and alert on unusual SNMP traffic patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1499.004 which covers network denial of service attacks, and organizations should consider implementing intrusion detection systems that can identify and block malicious SNMP traffic patterns. Additionally, regular security assessments and code reviews should be conducted to prevent similar issues where security patches introduce regressions, particularly in critical system components like network management daemons that form the backbone of enterprise monitoring infrastructure.