CVE-2018-19199 in uriparser
Summary
by MITRE
An issue was discovered in uriparser before 0.9.0. UriQuery.c allows an integer overflow via a uriComposeQuery* or uriComposeQueryEx* function because of an unchecked multiplication.
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Analysis
by VulDB Data Team • 06/05/2023
The vulnerability identified as CVE-2018-19199 resides within the uriparser library version 0.8.4 and earlier, representing a critical integer overflow flaw that can lead to arbitrary code execution or denial of service conditions. This issue specifically affects the UriQuery.c component of the library, which is responsible for handling URI query string parsing and composition operations. The vulnerability manifests when applications utilize the uriComposeQuery or uriComposeQueryEx functions to construct query strings from parsed URI components, creating a scenario where malicious input can trigger unexpected behavior in the underlying memory management and buffer allocation processes.
The technical root cause of this vulnerability stems from an unchecked multiplication operation within the uriComposeQuery and uriComposeQueryEx functions, which directly relates to CWE-190, Integer Overflow or Wraparound. The flaw occurs when the library attempts to calculate the required buffer size for composing query strings by multiplying the number of query parameters by the average length of each parameter. When an attacker supplies a large number of query parameters or parameters with extremely long lengths, the multiplication operation can exceed the maximum value that can be represented by the integer data type used for size calculations, resulting in an integer overflow. This overflow causes the library to allocate insufficient memory for the intended operation, potentially leading to buffer overflows, memory corruption, or other memory safety issues that can be exploited by malicious actors.
The operational impact of this vulnerability extends across numerous applications and systems that rely on the uriparser library for URI processing, including web servers, proxy applications, network monitoring tools, and any software that handles URI parsing and composition. Attackers can exploit this vulnerability by crafting malicious URIs with carefully constructed query parameters that trigger the integer overflow condition during the composition phase. This exploitation can result in application crashes, memory corruption, or potentially full system compromise depending on the execution environment and memory layout. The vulnerability is particularly concerning because it can be triggered through legitimate URI parsing operations without requiring special privileges or complex attack vectors, making it a significant risk for applications that process untrusted URI input from users or external sources.
Mitigation strategies for CVE-2018-19199 primarily involve upgrading to uriparser version 0.9.0 or later, where the integer overflow has been addressed through proper input validation and size calculation checks. System administrators and developers should also implement additional defensive measures such as input sanitization for URI components, limiting the maximum number of query parameters that can be processed, and implementing proper error handling for memory allocation failures. The vulnerability demonstrates the importance of proper integer overflow protection in memory-safe programming practices and aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1499.004 for Endpoint Denial of Service, as it can be leveraged to cause system instability or denial of service conditions. Organizations should also consider implementing runtime monitoring and anomaly detection for URI processing functions to identify potential exploitation attempts and maintain comprehensive patch management procedures to ensure all systems utilizing uriparser are protected against this and similar vulnerabilities.