CVE-2008-1742 in Unified Communications Manager
Summary
by MITRE
Memory leak in the Certificate Trust List (CTL) Provider service in Cisco Unified Communications Manager (CUCM) 5.x before 5.1(3) allows remote attackers to cause a denial of service (memory consumption and service interruption) via a series of malformed TCP packets, as demonstrated by TCPFUZZ, aka Bug ID CSCsj80609.
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Analysis
by VulDB Data Team • 08/10/2019
The vulnerability described in CVE-2008-1742 represents a critical memory leak condition within Cisco Unified Communications Manager's Certificate Trust List Provider service. This flaw exists in CUCM versions 5.x prior to 5.1(3) and specifically affects the CTL service responsible for managing certificate trust relationships within the communication infrastructure. The vulnerability manifests when the system processes malformed TCP packets, leading to progressive memory consumption that ultimately results in service disruption and denial of service conditions. The issue was identified and documented as Bug ID CSCsj80609, highlighting its significance within Cisco's internal tracking systems. The vulnerability's impact extends beyond simple resource exhaustion as it fundamentally compromises the availability of critical communication services that organizations depend upon for business continuity.
The technical mechanism behind this vulnerability involves the improper handling of malformed TCP packet sequences by the CTL Provider service component. When the service receives these specially crafted packets, it fails to properly release allocated memory resources during the processing of malformed data structures. This memory management failure creates a progressive leak where each malicious packet consumption adds to the system's memory footprint without corresponding release operations. The vulnerability is particularly insidious because it can be triggered remotely without requiring authentication or privileged access, making it an attractive target for attackers seeking to disrupt communication services. The TCPFUZZ demonstration tool specifically exploits this weakness by sending carefully constructed packet sequences that cause the memory leak to accumulate rapidly, eventually exhausting available system resources.
The operational impact of this vulnerability is severe and multifaceted, affecting organizations that rely on Cisco Unified Communications Manager for their voice and video communication infrastructure. When exploited successfully, the memory leak causes progressive system degradation that can lead to complete service interruption, preventing legitimate users from establishing communication sessions. The denial of service condition affects not only the CTL service itself but can also impact the broader CUCM environment, potentially causing cascading failures in related communication services. Organizations may experience extended downtime, loss of productivity, and potential business disruption as the system becomes increasingly unstable. The vulnerability's remote exploitability means that attackers can target these services from outside the network perimeter, making it particularly dangerous for organizations with exposed communication infrastructure.
Mitigation strategies for this vulnerability require immediate patching of affected CUCM systems to version 5.1(3) or later, which contains the necessary fixes for the memory leak condition. Network administrators should implement TCP packet filtering rules to restrict access to the affected CTL service ports and consider deploying intrusion detection systems that can identify and block malformed packet patterns. Organizations should also monitor system memory usage closely and implement automated alerting for unusual memory consumption patterns that could indicate exploitation attempts. The vulnerability aligns with CWE-401, which specifically addresses improper handling of memory allocation and deallocation, and demonstrates characteristics consistent with ATT&CK technique T1499.004 for network denial of service attacks. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of affected software versions within the network infrastructure.