CVE-2004-0580 in Linksys
Summary
by MITRE
DHCP on Linksys BEFSR11, BEFSR41, BEFSR81, and BEFSRU31 Cable/DSL Routers, firmware version 1.45.7, does not properly clear previously used buffer contents in a BOOTP reply packet, which allows remote attackers to obtain sensitive information.
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Analysis
by VulDB Data Team • 05/17/2025
The vulnerability identified as CVE-2004-0580 affects several Linksys Cable/DSL router models including the BEFSR11, BEFSR41, BEFSR81, and BEFSRU31 devices running firmware version 1.45.7. This issue represents a classic buffer overflow scenario where the device fails to properly clear memory contents during the BOOTP (Bootstrap Protocol) reply process. The vulnerability resides in the router's handling of network packets and specifically impacts the way these devices manage memory allocation and data transmission within their DHCP implementation. The flaw allows remote attackers to potentially access sensitive information that may have been previously stored in memory buffers, creating a significant security risk for network infrastructure.
This technical weakness manifests through improper memory management practices during the BOOTP reply packet construction process. When the affected routers respond to BOOTP requests, they fail to adequately clear previously used buffer contents before reusing those memory locations for new packet data. This behavior creates a situation where remnants of previous network communications, including potentially sensitive data, may persist in memory and inadvertently become part of subsequent network responses. The vulnerability operates at the network protocol level and specifically targets the BOOTP implementation within the router's firmware, making it particularly dangerous as it can be exploited remotely without requiring physical access to the device or authentication credentials. The underlying cause can be categorized under CWE-129, which addresses improper validation of buffer boundaries, and also relates to CWE-772, concerning missing release of memory resources.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates potential attack vectors for more sophisticated exploitation attempts. Remote attackers can leverage this flaw to harvest sensitive information that may include network configuration details, previously processed network traffic data, or other confidential information stored in memory buffers. This information disclosure vulnerability could enable attackers to gain insights into network topology, device configurations, or other data that could facilitate subsequent attacks. The threat landscape for this vulnerability aligns with ATT&CK technique T1046, which involves discovery of network services and T1083, focusing on file and directory discovery, as attackers could use the leaked information to map network structures and identify potential targets. The vulnerability also supports ATT&CK technique T1566, related to credential access through social engineering, as the leaked data might include information useful for crafting targeted attacks against network users.
Mitigation strategies for CVE-2004-0580 should prioritize firmware updates from Linksys to address the memory management issue within the BOOTP implementation. Network administrators should also implement additional security controls including network segmentation to limit the potential impact of exploitation, firewall rules to restrict BOOTP/DHCP traffic to trusted sources, and monitoring systems to detect anomalous network behavior that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper memory management practices in embedded systems and network infrastructure devices, emphasizing the need for thorough security testing of firmware implementations. Organizations should also consider implementing network access control measures and regular security assessments to identify similar memory-related vulnerabilities in other network equipment. Given the age of this vulnerability and the specific firmware versions affected, the most effective remediation involves upgrading to newer firmware versions that properly address the buffer clearing mechanisms in the BOOTP implementation, thereby preventing unauthorized access to previously stored memory contents.