CVE-2016-1347 in IOS
Summary
by MITRE
The Wide Area Application Services (WAAS) Express implementation in Cisco IOS 15.1 through 15.5 allows remote attackers to cause a denial of service (device reload) via a crafted TCP segment, aka Bug ID CSCuq59708.
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Analysis
by VulDB Data Team • 10/15/2024
The vulnerability identified as CVE-2016-1347 resides within Cisco IOS implementations of Wide Area Application Services Express functionality, specifically affecting versions 15.1 through 15.5. This flaw manifests as a remote denial of service condition that can be triggered by sending a specially crafted TCP segment to affected devices. The vulnerability represents a critical weakness in the network infrastructure layer, as it allows unauthorized remote attackers to disrupt service availability without requiring authentication or privileged access. The bug was catalogued under Cisco Bug ID CSCuq59708, indicating its identification within Cisco's internal tracking system for software defects.
The technical mechanism behind this vulnerability involves improper handling of TCP segments within the WAAS Express module of Cisco IOS. When a maliciously crafted TCP packet is received by an affected device, the processing routine fails to properly validate or handle the packet structure, leading to a memory corruption condition that ultimately results in device system reload. This type of flaw falls under the category of improper input validation and memory management issues, which are commonly classified as CWE-121 for buffer overflow conditions or CWE-122 for buffer overflow in a different context. The vulnerability specifically targets the TCP processing stack within the WAAS implementation, where the device fails to properly sanitize incoming packet data before processing.
The operational impact of CVE-2016-1347 extends beyond simple service disruption as it can cause complete device unavailability, requiring manual intervention to restore normal operations. Network administrators face the challenge of maintaining service continuity while the affected devices undergo automatic reload cycles, potentially causing cascading failures in network infrastructure. This vulnerability directly impacts the availability aspect of the CIA triad and can be categorized under MITRE ATT&CK technique T1499.004 for Network Denial of Service. The attack surface includes any network device running affected Cisco IOS versions that have WAAS Express enabled, making it particularly dangerous for enterprise networks where such services are commonly deployed to optimize WAN performance.
Mitigation strategies for this vulnerability require immediate implementation of network segmentation and access control measures to limit exposure to untrusted networks. Cisco recommends applying the appropriate software patches and updates to resolve the issue, with the vulnerability being addressed through IOS software releases that include corrected TCP processing routines. Network administrators should disable WAAS Express functionality on affected devices until patches are applied, as this service is not essential for basic network operations. The remediation process involves careful planning to avoid service disruption during patch deployment, and organizations should conduct thorough testing in controlled environments before applying updates to production networks. Additionally, implementing network monitoring solutions that can detect anomalous TCP traffic patterns may help identify exploitation attempts and provide early warning of potential attacks against this vulnerability.