CVE-2011-2760 in BigIron RX switch
Summary
by MITRE
Brocade BigIron RX switches allow remote attackers to bypass ACL rules by using 179 as the source port of a packet.
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Analysis
by VulDB Data Team • 12/02/2024
The vulnerability identified as CVE-2011-2760 affects Brocade BigIron RX series switches, representing a significant security flaw in network access control implementation. This issue stems from improper handling of packet source port validation within the switch's access control list processing mechanism, creating a pathway for malicious actors to circumvent established network security policies. The vulnerability specifically manifests when packets are crafted with source port 179, which is traditionally associated with the Border Gateway Protocol commonly used in internet routing operations. This particular port selection exploits a design oversight in how the switch validates incoming packet headers against configured access control rules.
The technical exploitation of this vulnerability occurs through the manipulation of network packet headers, specifically targeting the source port field within IP packets. When a packet arrives at the switch with source port 179, the system fails to properly validate this information against the configured access control lists, allowing unauthorized traffic to pass through security controls that should have blocked it. This represents a fundamental flaw in the switch's packet inspection and filtering logic, where the system does not adequately distinguish between legitimate and malicious packet sources based on port information. The vulnerability essentially creates a backdoor mechanism that bypasses the normal ACL enforcement procedures, enabling attackers to establish unauthorized communication paths within the network infrastructure.
From an operational perspective, this vulnerability poses severe risks to network security and integrity, particularly in environments where strict access controls are essential for protecting sensitive data and maintaining network boundaries. Network administrators who rely on ACL rules for traffic filtering and security enforcement may find their protection mechanisms completely undermined, potentially allowing attackers to access internal network resources that should be restricted. The impact extends beyond simple traffic bypass, as this vulnerability could enable more sophisticated attacks including lateral movement within the network, data exfiltration, or establishment of command and control channels. The remote nature of the attack means that threat actors do not require physical access to the network infrastructure or direct network connection to exploit the vulnerability, making it particularly dangerous in distributed network environments.
The security implications of CVE-2011-2760 align with CWE-284, which addresses improper access control issues in network security implementations, and can be mapped to ATT&CK technique T1071.004 for application layer protocol usage, specifically targeting Border Gateway Protocol communications. Organizations affected by this vulnerability should implement immediate mitigations including firmware updates from Brocade, temporary network segmentation to isolate affected switches, and enhanced monitoring of traffic patterns involving source port 179. Network administrators should also consider implementing additional security controls such as intrusion detection systems and traffic analysis tools to detect anomalous patterns that might indicate exploitation attempts. The vulnerability highlights the critical importance of thorough security testing of network infrastructure components and demonstrates how seemingly minor implementation flaws can create significant security weaknesses in enterprise network environments.