CVE-2016-1544 in nghttp2
Summary
by MITRE
nghttp2 before 1.7.1 allows remote attackers to cause a denial of service (memory exhaustion).
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Analysis
by VulDB Data Team • 10/14/2024
The vulnerability identified as CVE-2016-1544 affects nghttp2 versions prior to 1.7.1 and represents a critical memory exhaustion issue that can be exploited by remote attackers to cause denial of service conditions. This flaw specifically impacts the HTTP/2 implementation library that is widely used in web servers, proxies, and client applications. The vulnerability stems from insufficient input validation and memory management practices within the nghttp2 library's handling of HTTP/2 frames and streams. When processing specially crafted HTTP/2 requests, the library fails to properly limit memory allocation, allowing malicious actors to consume excessive system resources and potentially crash the affected service.
The technical root cause of this vulnerability lies in the improper handling of HTTP/2 stream and frame processing within the nghttp2 library. Attackers can exploit this weakness by sending carefully constructed HTTP/2 requests that trigger unbounded memory allocation patterns. The flaw manifests when the library processes headers and frames without adequate bounds checking on the number of streams, frame sizes, or header compression parameters. This allows an attacker to cause the application to allocate memory continuously until system resources are exhausted, leading to service disruption. The vulnerability is particularly dangerous because HTTP/2 is increasingly adopted in modern web infrastructure, making numerous applications and services susceptible to this attack vector.
From an operational impact perspective, this vulnerability can severely compromise the availability of web services that rely on nghttp2 for HTTP/2 functionality. Systems using affected versions may experience complete service outages, requiring manual intervention to restore normal operations. The memory exhaustion can occur rapidly, making it difficult for administrators to respond effectively. Additionally, the vulnerability affects a wide range of applications including web servers like nginx and Apache httpd, proxy servers, and client applications that utilize the nghttp2 library. The impact extends beyond simple service disruption to potentially affecting business continuity and user experience across multiple platforms that depend on HTTP/2 connectivity.
Organizations should immediately upgrade to nghttp2 version 1.7.1 or later to remediate this vulnerability. The patch addresses the memory management issues by implementing proper bounds checking on frame processing and stream allocation limits. Administrators should also implement network-level mitigations such as rate limiting and connection tracking to reduce the impact of potential attacks. Monitoring systems should be configured to detect unusual memory consumption patterns that may indicate exploitation attempts. The vulnerability aligns with CWE-400 which catalogs improper resource management issues, and represents a specific instance of resource exhaustion attacks that fall under the ATT&CK technique T1499.1 for network denial of service. Organizations should conduct thorough testing of the updated library to ensure compatibility with existing applications while maintaining security posture against this and related memory exhaustion threats.