CVE-2014-3357 in IOS
Summary
by MITRE
Cisco IOS 15.0, 15.1, 15.2, and 15.4 and IOS XE 3.3.xSE before 3.3.2SE, 3.3.xXO before 3.3.1XO, 3.5.xE before 3.5.2E, and 3.11.xS before 3.11.1S allow remote attackers to cause a denial of service (device reload) via malformed mDNS packets, aka Bug ID CSCul90866.
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Analysis
by VulDB Data Team • 02/21/2022
Cisco IOS and IOS XE software versions affected by CVE-2014-3357 present a critical vulnerability in the multicast domain name system implementation that enables remote attackers to trigger device reloads through carefully crafted malformed mDNS packets. This vulnerability resides in the network operating system's handling of multicast DNS traffic, specifically within the mDNS responder functionality that is part of the Cisco IOS software stack. The flaw affects multiple release branches including IOS 15.0, 15.1, 15.2, and 15.4, as well as various IOS XE versions such as 3.3.xSE, 3.3.xXO, 3.5.xE, and 3.11.xS, demonstrating the widespread nature of this mDNS processing weakness. The vulnerability is categorized under CWE-121 as a buffer overflow condition that occurs when the system fails to properly validate incoming mDNS packet structures before processing them. This allows attackers to craft packets that contain malformed data structures which, when processed by the affected Cisco devices, cause the system to crash and subsequently reload.
The operational impact of this vulnerability extends beyond simple service disruption as it represents a denial of service attack vector that can be exploited remotely without authentication requirements, making it particularly dangerous in network environments where Cisco devices serve as core infrastructure components. Network administrators face the risk of unauthorized parties causing repeated device reloads that can result in network outages, service interruptions, and potential cascading failures throughout the connected network infrastructure. The vulnerability's exploitation mechanism specifically targets the mDNS packet parsing logic within the IOS kernel, where insufficient input validation allows malformed packets to trigger memory corruption conditions that lead to system instability and forced device restarts. This creates a persistent threat where attackers can repeatedly cause service disruption by simply sending crafted mDNS packets to affected devices, potentially leading to significant operational downtime and resource consumption during recovery processes.
Mitigation strategies for CVE-2014-3357 should focus on implementing network segmentation and access control measures to limit exposure to untrusted networks, particularly where mDNS traffic might originate from external sources. Cisco recommends applying the appropriate software patches and upgrades to affected IOS and IOS XE versions, with the specific releases containing fixes for this vulnerability being identified in the respective release notes for each affected branch. Network security teams should consider implementing ingress filtering and packet inspection rules that can identify and drop malformed mDNS traffic before it reaches the vulnerable system components. The implementation of network monitoring solutions that can detect unusual reload patterns or mDNS traffic anomalies provides additional layers of defense against exploitation attempts. Organizations should also evaluate their mDNS service configurations to determine if these services are required in production environments, as disabling unnecessary mDNS functionality can eliminate the attack surface entirely. This vulnerability aligns with ATT&CK technique T1499.004 for network denial of service attacks and represents a classic example of how protocol implementation flaws can lead to critical system availability compromises. The vulnerability demonstrates the importance of robust input validation and proper error handling in network protocol implementations, particularly for services that process untrusted network traffic from external sources.