CVE-2005-2177 in Solaris
Summary
by MITRE
Net-SNMP 5.0.x before 5.0.10.2, 5.2.x before 5.2.1.2, and 5.1.3, when net-snmp is using stream sockets such as TCP, allows remote attackers to cause a denial of service (daemon hang and CPU consumption) via a TCP packet of length 1, which triggers an infinite loop.
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Analysis
by VulDB Data Team • 06/08/2019
The vulnerability described in CVE-2005-2177 represents a critical denial of service flaw affecting Net-SNMP versions prior to specific patch releases. This issue specifically impacts the SNMP daemon when operating in stream socket mode using TCP protocols, making it a significant concern for network infrastructure systems that rely on SNMP monitoring and management. The vulnerability stems from inadequate input validation mechanisms within the SNMP daemon's TCP packet processing routines, creating a scenario where malformed packets can trigger system instability.
The technical flaw manifests when the Net-SNMP daemon receives a TCP packet with a length of exactly one byte. This seemingly innocuous packet triggers an infinite loop within the daemon's processing logic, causing the system to consume excessive CPU resources while remaining unresponsive to legitimate network traffic. The vulnerability operates at the protocol parsing level where the daemon fails to properly validate packet sizes before entering processing loops, creating a condition where a single malformed packet can cause sustained resource exhaustion. This type of vulnerability falls under CWE-121, which encompasses buffer overflow conditions, though specifically manifests as an infinite loop rather than direct memory corruption.
The operational impact of this vulnerability extends beyond simple service disruption to create potential cascading effects within network management systems. When exploited, the daemon hang and CPU consumption can render network monitoring capabilities ineffective, potentially masking other security issues or preventing administrators from detecting genuine network problems. Organizations relying on SNMP for network monitoring, system health checks, and device management face significant risk as the daemon becomes unresponsive to legitimate queries while consuming system resources. This vulnerability particularly affects enterprise environments where SNMP is widely used for network infrastructure management and where the daemon's stability directly impacts business continuity.
Mitigation strategies for this vulnerability require immediate patching of affected Net-SNMP installations to versions 5.0.10.2, 5.2.1.2, or 5.1.3, which contain the necessary code modifications to properly validate packet lengths before processing. Network administrators should implement TCP packet filtering rules to block malformed packets at network boundaries, though this approach provides only partial protection as the vulnerability can be triggered through various attack vectors. The fix involves implementing proper input validation routines that check packet size constraints before entering processing loops, preventing the infinite loop condition that leads to resource exhaustion. This vulnerability demonstrates the importance of proper input validation in network services and aligns with ATT&CK technique T1499.001, which covers network denial of service attacks targeting service availability. Organizations should also consider implementing monitoring solutions to detect unusual CPU consumption patterns that might indicate exploitation attempts, as the vulnerability creates predictable resource consumption behavior that can be detected through proper system monitoring.