CVE-2019-12835 in Leanify
Summary
by MITRE
formats/xml.cpp in Leanify 0.4.3 allows for a controlled out-of-bounds write in xml_memory_writer::write via characters that require escaping.
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Analysis
by VulDB Data Team • 10/05/2023
The vulnerability identified as CVE-2019-12835 resides within the Leanify 0.4.3 software package, specifically in the formats/xml.cpp file where an out-of-bounds write condition occurs during XML processing operations. This flaw manifests when the xml_memory_writer::write function encounters characters that require escaping, creating a scenario where the application fails to properly validate memory boundaries before writing data. The issue represents a critical security concern as it allows for potentially arbitrary code execution or system compromise through controlled input manipulation.
The technical implementation of this vulnerability stems from improper boundary checking within the XML memory writer component. When processing XML content containing special characters that require escaping, the software does not adequately validate the destination buffer size against the required output length. This memory management failure creates an opportunity for attackers to craft malicious XML input that, when processed by Leanify, triggers an out-of-bounds write operation. The flaw falls under the category of buffer overflow vulnerabilities and aligns with CWE-121, which describes stack-based buffer overflow conditions, though the specific implementation appears to involve heap memory management issues.
Operational impact of this vulnerability extends beyond simple data corruption, as it can enable remote code execution when Leanify processes untrusted XML input. Attackers can exploit this weakness by providing specially crafted XML content that, upon processing, causes the application to write beyond allocated memory boundaries. This behavior can lead to application crashes, denial of service conditions, or potentially more severe consequences including arbitrary code execution depending on the execution environment and memory layout. The vulnerability is particularly dangerous in automated processing environments where Leanify might handle XML files from untrusted sources without proper sanitization.
Mitigation strategies for CVE-2019-12835 should begin with immediate software updates to versions that address the identified memory management flaw. Organizations should implement strict input validation procedures for all XML processing activities, including sanitization of special characters and enforcement of proper buffer size limits. The implementation of address space layout randomization and stack canaries can provide additional protection layers against exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to techniques involving memory corruption and privilege escalation, requiring defensive measures that include application whitelisting, network segmentation, and comprehensive monitoring of XML processing activities to detect anomalous behavior patterns.
The vulnerability demonstrates the critical importance of proper memory management in parsing libraries and highlights the need for rigorous input validation in XML processing components. Security teams should conduct thorough vulnerability assessments of all XML handling components within their infrastructure and implement automated scanning tools to identify similar memory corruption issues. Regular security updates and patch management processes are essential to maintain protection against such flaws. Additionally, developers should adopt secure coding practices that emphasize buffer size validation and proper memory allocation techniques to prevent similar issues from emerging in future implementations.