CVE-2018-21270 in stringstream Module
Summary
by MITRE • 12/04/2020
Versions less than 0.0.6 of the Node.js stringstream module are vulnerable to an out-of-bounds read because of allocation of uninitialized buffers when a number is passed in the input stream (when using Node.js 4.x).
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Analysis
by VulDB Data Team • 12/12/2020
The vulnerability identified as CVE-2018-21270 affects the Node.js stringstream module version 0.0.5 and earlier, representing a critical security flaw that manifests through improper buffer handling during data processing. This issue specifically targets applications utilizing Node.js version 4.x where the module processes numeric input streams, creating a scenario where uninitialized memory segments are accessed during buffer allocation operations. The vulnerability stems from the module's failure to properly initialize memory buffers before processing input data, leading to potential exposure of sensitive information from adjacent memory locations.
The technical implementation of this vulnerability resides in the module's buffer management mechanism where numeric input parameters trigger allocation of uninitialized memory segments. When a number is passed through the input stream, the stringstream module allocates memory buffers without proper initialization, creating a condition where the application may read from memory locations that contain previously allocated data. This out-of-bounds read behavior occurs because the module does not enforce proper memory initialization protocols before processing numeric input streams, resulting in the exposure of potentially sensitive data from the uninitialized buffer segments.
From an operational impact perspective, this vulnerability presents significant risks to applications that process user-supplied numeric data through the stringstream module, particularly in environments running Node.js 4.x. Attackers could potentially exploit this weakness to extract sensitive information from memory, including cryptographic keys, session tokens, or other confidential data that may reside in the uninitialized buffer regions. The vulnerability's exploitation requires minimal input manipulation and can occur during normal application operation when numeric data is processed through the affected module, making it particularly dangerous for applications handling sensitive information.
The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software implementations, and demonstrates characteristics consistent with memory safety issues in node.js runtime environments. From an attack framework perspective, this weakness could be categorized under the data exposure category in the MITRE ATT&CK framework, specifically related to information gathering and credential access techniques. The vulnerability's impact is amplified in environments where Node.js 4.x is still in use, as this version reached end-of-life status and no longer receives security updates, leaving systems vulnerable to exploitation.
Mitigation strategies for this vulnerability require immediate upgrade of the stringstream module to version 0.0.6 or later, which includes proper buffer initialization mechanisms. Organizations should conduct comprehensive vulnerability assessments to identify all applications utilizing the affected module and ensure complete remediation through version updates. Additionally, implementing runtime monitoring and input validation controls can provide additional defense-in-depth measures, while regular security audits should verify that no legacy code paths remain using vulnerable module versions. The most effective remediation approach involves complete migration away from Node.js 4.x to supported versions, as this platform no longer receives security patches and presents multiple additional vulnerabilities beyond this specific issue.