CVE-2010-0576 in IOS
Summary
by MITRE
Unspecified vulnerability in Cisco IOS 12.0 through 12.4, IOS XE 2.1.x through 2.3.x before 2.3.2, and IOS XR 3.2.x through 3.4.3, when Multiprotocol Label Switching (MPLS) and Label Distribution Protocol (LDP) are enabled, allows remote attackers to cause a denial of service (device reload or process restart) via a crafted LDP packet, aka Bug IDs CSCsz45567 and CSCsj25893.
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Analysis
by VulDB Data Team • 05/03/2026
This vulnerability exists within Cisco IOS operating systems across multiple versions including 12.0 through 12.4, IOS XE 2.1.x through 2.3.x before 2.3.2, and IOS XR 3.2.x through 3.4.3. The flaw specifically manifests when Multiprotocol Label Switching and Label Distribution Protocol are simultaneously enabled on affected devices. The vulnerability represents a remote code execution risk that can be exploited by attackers positioned outside the network perimeter, making it particularly dangerous for network infrastructure devices that are inherently exposed to external traffic. The issue stems from insufficient input validation within the LDP implementation, which processes incoming packets without proper sanitization of malformed or crafted data structures.
The technical exploitation occurs through the delivery of specially crafted LDP packets that trigger buffer overflows or memory corruption within the IOS processing stack. When these malformed packets are received and processed by the affected devices, they cause the underlying software components to behave unpredictably, resulting in system instability. The vulnerability specifically targets the label distribution protocol which is responsible for establishing and maintaining label bindings between network routers in an MPLS environment. This protocol is critical for proper network operation as it enables efficient packet forwarding across the MPLS domain. The flaw falls under the CWE-121 category of Stack-based Buffer Overflow, which is classified as a common weakness in software development practices that leads to memory corruption vulnerabilities.
The operational impact of this vulnerability is significant as it can result in complete device reloads or process restarts, effectively causing denial of service across the entire network segment served by the compromised router. Network administrators may experience extended downtime as devices require manual intervention to recover from the restart conditions, and in some cases, the device may enter a continuous restart loop. The vulnerability affects core network infrastructure components that are essential for maintaining connectivity and service availability, making it a critical concern for enterprise and service provider networks. The attack vector requires only network access to send malicious LDP packets, making it relatively easy to exploit and potentially affecting multiple devices within the same MPLS domain.
Cisco has addressed this vulnerability through software updates and patches that include enhanced input validation and memory management routines for the LDP protocol processing. Organizations should implement immediate mitigation strategies including disabling MPLS and LDP functionality when not required, implementing network segmentation to isolate vulnerable devices, and applying the latest security patches from Cisco. The vulnerability aligns with ATT&CK technique T1499.002 for network denial of service attacks, and represents a classic example of how protocol-level vulnerabilities can be exploited to compromise network availability. Network monitoring should be enhanced to detect anomalous LDP packet patterns, and baseline network behavior should be established to quickly identify potential exploitation attempts. The incident underscores the importance of proper input validation in network protocol implementations and highlights the critical nature of maintaining up-to-date security patches in enterprise network infrastructure.