CVE-2008-1749 in Cisco Content Switching Module Ssl
Summary
by MITRE
Memory leak in Cisco Content Switching Module (CSM) 4.2(3) up to 4.2(8) and Cisco Content Switching Module with SSL (CSM-S) 2.1(2) up to 2.1(7) allows remote attackers to cause a denial of service (memory consumption) via TCP segments with an unspecified combination of TCP flags.
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Analysis
by VulDB Data Team • 08/10/2019
The vulnerability identified as CVE-2008-1749 represents a critical memory leak issue affecting Cisco Content Switching Module (CSM) and Cisco Content Switching Module with SSL (CSM-S) products. This flaw exists within specific software versions of Cisco's content switching hardware, namely CSM 4.2(3) through 4.2(8) and CSM-S 2.1(2) through 2.1(7). The vulnerability operates at the network protocol level, specifically targeting the TCP protocol implementation within these switching modules, making it particularly dangerous for network infrastructure components that handle high volumes of traffic.
The technical mechanism of this vulnerability involves the improper handling of TCP segments that contain specific combinations of TCP flags. When remote attackers craft and send specially formatted TCP packets with these particular flag combinations, the affected CSM and CSM-S devices fail to properly manage their memory allocation. This results in a progressive consumption of available memory resources within the switching module, ultimately leading to system instability and potential complete service disruption. The vulnerability demonstrates characteristics consistent with CWE-401, which describes improper handling of memory allocation and deallocation, specifically focusing on memory leaks that occur when system resources are not properly released after use.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it can severely compromise the availability and reliability of network services that depend on these content switching modules. Network administrators may experience gradual degradation of service performance before complete system failure occurs, making the issue particularly challenging to detect and remediate in production environments. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter without requiring physical access or authentication credentials, aligning with ATT&CK technique T1499.004 for network denial of service attacks. Organizations relying on these switching modules for load balancing, content switching, or SSL termination services face significant risk of service interruptions that could affect business operations and customer access to critical applications.
Mitigation strategies for this vulnerability require immediate implementation of software updates and patches provided by Cisco to address the memory leak issue in affected versions. Network administrators should prioritize upgrading to patched versions of the CSM and CSM-S software, as these releases contain the necessary fixes to properly handle TCP segment processing and prevent memory consumption anomalies. Additionally, implementing network monitoring solutions that can detect unusual memory usage patterns or traffic anomalies may help identify exploitation attempts before they cause significant service disruption. Organizations should also consider implementing access control measures to limit exposure to the vulnerable devices and establish network segmentation strategies that reduce the potential impact of successful exploitation attempts. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date network infrastructure software and implementing robust vulnerability management processes to protect against known security flaws that could compromise network availability and service continuity.