CVE-2018-7247 in Leptonica
Summary
by MITRE
An issue was discovered in pixHtmlViewer in prog/htmlviewer.c in Leptonica before 1.75.3. Unsanitized input (rootname) can overflow a buffer, leading potentially to arbitrary code execution or possibly unspecified other impact.
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Analysis
by VulDB Data Team • 02/08/2023
The vulnerability identified as CVE-2018-7247 resides within the pixHtmlViewer component of the Leptonica library version 1.75.2 and earlier, representing a critical buffer overflow flaw that can potentially lead to arbitrary code execution. This issue specifically affects the prog/htmlviewer.c file where the rootname parameter is processed without proper input sanitization, creating an exploitable condition that adversaries can leverage to compromise systems running vulnerable software.
The technical root cause of this vulnerability stems from inadequate bounds checking and input validation within the html viewer functionality. When the application processes user-provided input through the rootname parameter, it fails to properly sanitize or limit the length of this input before using it to populate a fixed-size buffer. This classic buffer overflow condition occurs because the application does not verify that the input data fits within the allocated memory space, allowing attackers to overflow the buffer and potentially overwrite adjacent memory locations including return addresses and control data structures. The vulnerability manifests as a direct consequence of poor memory management practices and insufficient input validation mechanisms.
The operational impact of CVE-2018-7247 extends beyond simple denial of service conditions to encompass full system compromise capabilities. An attacker who successfully exploits this vulnerability can execute arbitrary code with the privileges of the affected application, potentially leading to complete system takeover. This vulnerability is particularly dangerous in environments where the affected software is used to process untrusted input from web applications, document processing systems, or automated image analysis pipelines. The potential for remote code execution makes this vulnerability attractive to threat actors seeking to establish persistent access to target systems, as it can be exploited through web-based attacks or by tricking users into opening malicious documents containing crafted input.
This vulnerability aligns with CWE-121, which describes the weakness of stack-based buffer overflow conditions, and also relates to CWE-787, which covers out-of-bounds write vulnerabilities. From an adversarial perspective, this flaw maps to multiple ATT&CK techniques including T1059 for command and scripting interpreter execution and T1203 for exploitation for privilege escalation. The vulnerability's exploitation typically requires a scenario where an attacker can influence the rootname parameter through a crafted input stream, making it particularly relevant in web application contexts or document processing environments where user input is not properly sanitized before being passed to the vulnerable library functions.
Mitigation strategies for CVE-2018-7247 should prioritize immediate patching of the Leptonica library to version 1.75.3 or later, which contains the necessary fixes to address the buffer overflow condition. Organizations should also implement input validation measures at application boundaries to prevent unsanitized data from reaching the vulnerable code paths, including length restrictions and proper parameter sanitization. Network segmentation and access controls should be enforced to limit exposure of systems running vulnerable versions of the library, while security monitoring should be enhanced to detect potential exploitation attempts through anomalous input patterns or unusual memory access behaviors. Additionally, regular security assessments should be conducted to identify and remediate similar vulnerabilities in other third-party libraries and components within the software supply chain.