CVE-2019-3554 in AcceptRoutingHandler
Summary
by MITRE
Wangle's AcceptRoutingHandler incorrectly casts a socket when accepting a TLS 1.3 connection, leading to a potential denial of service attack against systems accepting such connections. This affects versions of Wangle prior to v2019.01.14.00
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Analysis
by VulDB Data Team • 07/01/2023
The vulnerability identified as CVE-2019-3554 resides within Wangle, a high-performance C++ networking framework developed by Facebook. This issue manifests in the AcceptRoutingHandler component which is responsible for managing incoming connection requests and routing them appropriately. The flaw specifically impacts systems that process TLS 1.3 connections, creating a potential vector for denial of service attacks that could compromise the availability of network services. The vulnerability affects all versions of Wangle prior to the release v2019.01.14.00, indicating that organizations using older versions remain at risk of exploitation. The technical implementation of TLS 1.3 handling within the framework contains a critical casting error that manifests during the connection acceptance phase, fundamentally altering how socket objects are processed and potentially leading to system instability or complete service disruption.
The core technical flaw involves an incorrect type casting operation within the AcceptRoutingHandler when processing TLS 1.3 connections. This improper casting occurs during the socket acceptance process where the framework attempts to convert or reinterpret socket objects in a manner that violates expected type safety protocols. The vulnerability stems from a lack of proper type validation and casting safeguards that should occur when handling the specific protocol negotiation required for TLS 1.3 connections. When a client attempts to establish a TLS 1.3 connection, the framework's AcceptRoutingHandler receives the socket object and performs an unsafe cast operation that can result in memory corruption or undefined behavior. This type of casting error falls under the CWE-121 category of stack-based buffer overflow conditions, though the specific manifestation in this case involves improper type handling rather than traditional buffer overflows. The flaw is particularly dangerous because TLS 1.3 connections are increasingly common in modern secure communications, making the attack surface more extensive than typical protocol handling vulnerabilities.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire network infrastructure relying on Wangle for connection management. An attacker exploiting this vulnerability can craft malicious TLS 1.3 connection requests that trigger the improper casting behavior, leading to denial of service conditions where legitimate users cannot establish connections to affected services. The nature of the vulnerability means that systems processing TLS 1.3 connections become unstable and may crash or become unresponsive, effectively preventing legitimate network traffic from being processed. This creates cascading effects in distributed systems where multiple services depend on Wangle for their networking capabilities, potentially leading to widespread service outages. The vulnerability's impact is amplified because TLS 1.3 is designed to be more efficient and secure than previous versions, making it the preferred choice for modern applications, thus increasing the likelihood that affected systems will be targeted. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique related to network denial of service and the T1595.001 technique involving network infiltration through protocol manipulation, representing a critical threat to operational continuity and service availability.
Organizations affected by CVE-2019-3554 should immediately upgrade to Wangle version v2019.01.14.00 or later to remediate the vulnerability, as this release contains the necessary patches to address the improper casting behavior in AcceptRoutingHandler. System administrators should conduct thorough vulnerability assessments to identify all instances of Wangle in use across their infrastructure, particularly in environments handling TLS 1.3 connections. The patch implementation should be performed with careful monitoring to ensure that the upgrade does not introduce compatibility issues with existing applications or services. Additionally, organizations should implement network segmentation and monitoring to detect unusual connection patterns that might indicate exploitation attempts, as the vulnerability may be used in conjunction with other attack vectors. Security teams should also consider implementing rate limiting and connection throttling mechanisms as defensive measures against potential exploitation attempts, while maintaining regular security updates to prevent similar vulnerabilities from emerging in other components of their networking infrastructure.