CVE-2015-1892 in Security Access Manager for Web
Summary
by MITRE
The Multicast DNS (mDNS) responder in IBM Security Access Manager for Web 7.x before 7.0.0 FP12 and 8.x before 8.0.1 FP1 inadvertently responds to unicast queries with source addresses that are not link-local, which allows remote attackers to cause a denial of service (traffic amplification) or obtain potentially sensitive information via port-5353 UDP packets.
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Analysis
by VulDB Data Team • 11/05/2024
The vulnerability identified as CVE-2015-1892 affects IBM Security Access Manager for Web versions 7.x before 7.0.0 FP12 and 8.x before 8.0.1 FP1, specifically targeting the Multicast DNS responder implementation. This flaw represents a significant security weakness in the network discovery protocol handling mechanism that could be exploited by remote attackers to compromise system availability and potentially access sensitive information. The issue stems from improper validation of source addresses in unicast query responses, creating a vector for malicious activity that aligns with common patterns of denial of service attacks targeting DNS infrastructure.
The technical implementation flaw occurs within the mDNS responder component that processes incoming UDP packets on port 5353, which is the standard port for multicast DNS communications. When the system receives unicast queries from source addresses that are not link-local, the responder incorrectly processes these requests and responds with potentially sensitive information or amplifies network traffic. This behavior violates standard network protocol expectations where mDNS typically operates within link-local addressing ranges and should not respond to queries from non-local addresses without proper validation. The vulnerability specifically manifests when the responder fails to validate that incoming unicast queries originate from legitimate link-local addresses, allowing arbitrary remote systems to trigger responses that can be exploited for traffic amplification attacks.
The operational impact of this vulnerability extends beyond simple denial of service conditions to include potential information disclosure risks that could expose sensitive system details to remote attackers. Attackers can leverage this flaw to perform traffic amplification attacks by sending small queries to the vulnerable system, which then responds with significantly larger responses that can overwhelm network resources and potentially reveal internal system information. The vulnerability creates an environment where remote adversaries can consume network bandwidth and processing resources while potentially gaining insights into the internal network structure, making it particularly dangerous in enterprise environments where IBM Security Access Manager for Web typically serves as a critical access control point. This weakness directly impacts the availability and confidentiality aspects of the system's security posture, as outlined in the CIA triad principles.
Mitigation strategies for CVE-2015-1892 should focus on implementing proper source address validation within the mDNS responder configuration and applying the available security patches from IBM. Organizations should configure their systems to reject unicast queries from non-link-local addresses and ensure that the mDNS responder only processes legitimate network discovery requests from expected source ranges. Network segmentation and firewall rules can provide additional protection by restricting access to port 5353 from unauthorized external sources, while also implementing monitoring to detect unusual traffic patterns that might indicate exploitation attempts. This vulnerability is categorized under CWE-200 for Information Exposure and CWE-400 for Uncontrolled Resource Consumption, and aligns with ATT&CK techniques related to denial of service and information gathering through network protocols. The most effective long-term solution involves upgrading to patched versions of IBM Security Access Manager for Web that address this specific mDNS responder behavior and implement proper validation controls for incoming network queries.