CVE-2010-0137 in IOS XR
Summary
by MITRE
Unspecified vulnerability in the sshd_child_handler process in the SSH server in Cisco IOS XR 3.4.1 through 3.7.0 allows remote attackers to cause a denial of service (process crash and memory consumption) via a crafted SSH2 packet, aka Bug ID CSCsu10574.
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Analysis
by VulDB Data Team • 04/11/2025
The vulnerability identified as CVE-2010-0137 represents a critical weakness in Cisco IOS XR software affecting versions 3.4.1 through 3.7.0. This issue specifically targets the sshd_child_handler process within the SSH server implementation, creating a remote attack vector that can be exploited by malicious actors to disrupt network services. The vulnerability falls under the category of denial of service attacks, where the targeted system experiences process crashes and excessive memory consumption, ultimately leading to service unavailability.
The technical flaw manifests through the improper handling of crafted SSH2 packets by the sshd_child_handler process. When the SSH server receives specially constructed packets, the processing logic fails to properly validate or sanitize the incoming data, causing the child process to crash unexpectedly. This malformed packet processing triggers memory allocation issues within the sshd_child_handler component, leading to memory exhaustion that can cascade into broader system instability. The vulnerability demonstrates poor input validation and error handling practices that are commonly associated with buffer overflow conditions and memory management flaws.
The operational impact of this vulnerability extends beyond simple service disruption, as it can affect critical network infrastructure components running Cisco IOS XR software. Network administrators managing routers, switches, and service provider equipment that utilize these vulnerable versions face potential service outages that could impact large-scale network operations. The remote nature of the attack means that adversaries can exploit this weakness from outside the network perimeter, making it particularly dangerous for publicly accessible network devices. Organizations with extensive deployments of Cisco IOS XR systems may experience cascading failures if multiple devices are affected simultaneously.
This vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and demonstrates characteristics consistent with the ATT&CK technique T1499.004 for network denial of service. The weakness creates a persistent attack surface that can be exploited repeatedly without requiring authentication or specific system access. Mitigation strategies should include immediate deployment of Cisco's security patches and advisories, network segmentation to limit exposure, and implementation of intrusion detection systems to monitor for suspicious SSH traffic patterns. Additionally, organizations should consider implementing rate limiting and connection monitoring to detect and prevent exploitation attempts that consume excessive system resources. The vulnerability underscores the importance of regular security updates and proper input validation in network infrastructure software to prevent similar issues from compromising operational continuity and network availability.