CVE-2001-0270 in Forethought
Summary
by MITRE
Marconi ASX-1000 ASX switches allow remote attackers to cause a denial of service in the telnet and web management interfaces via a malformed packet with the SYN-FIN and More Fragments attributes set.
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Analysis
by VulDB Data Team • 08/28/2024
The Marconi ASX-1000 ASX switch vulnerability represents a critical denial of service flaw that affects both telnet and web management interfaces of the device. This vulnerability stems from improper handling of network packets that contain specific combinations of TCP flags and fragment attributes. The flaw specifically manifests when a malformed packet is sent to the switch with both the SYN and FIN flags set simultaneously along with the More Fragments attribute enabled. This particular packet construction triggers a buffer overflow condition in the switch's network processing routines, causing the device to become unresponsive and effectively denying legitimate network access to authorized users.
The technical implementation of this vulnerability operates at the network protocol level, specifically targeting the TCP/IP stack implementation within the switch's firmware. When the switch receives a packet with the SYN-FIN flags set, it attempts to process this unusual combination as a normal connection termination sequence, but the More Fragments attribute causes the system to expect additional fragments that never arrive. This creates a memory management error where the switch's processing engine attempts to allocate memory for the fragmented data while simultaneously handling the connection termination logic. The resulting buffer overflow corrupts critical system memory structures and causes the switch to crash or become unresponsive, requiring manual intervention to restore normal operation.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network infrastructure availability and business continuity. Network administrators who rely on remote management capabilities through telnet and web interfaces face significant operational challenges when the switch becomes unavailable due to this attack. The vulnerability affects not only the management interfaces but also potentially impacts the switch's ability to forward network traffic normally, creating cascading effects throughout the network infrastructure. The attack requires minimal resources from the attacker, making it particularly dangerous as it can be executed remotely without authentication, and the effects are immediate and severe.
Mitigation strategies for this vulnerability should include immediate firmware updates from Marconi to address the buffer overflow condition in the TCP processing code. Network segmentation and access control measures should be implemented to restrict direct access to management interfaces from untrusted networks. The implementation of network intrusion detection systems can help identify and block malformed packets with the specific SYN-FIN fragment combinations. Additionally, administrators should disable unnecessary management protocols and implement strong authentication mechanisms for remaining access points. This vulnerability aligns with CWE-121, heap-based buffer overflow, and represents a technique consistent with ATT&CK tactic TA0005 (Defense Evasion) and technique T1499.002 (Network Denial of Service) in the MITRE ATT&CK framework, demonstrating how seemingly minor protocol inconsistencies can lead to significant operational impacts in network infrastructure devices.