CVE-2005-1141 in Optical Character Recognition Utility
Summary
by MITRE
Integer overflow in the readpgm function in pnm.c for GOCR 0.40, when using the netpbm library, allows remote attackers to execute arbitrary code via a PNM file with large width and height values, which leads to a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 07/22/2017
The vulnerability described in CVE-2005-1141 represents a critical integer overflow flaw within the GOCR optical character recognition software version 0.40. This issue specifically affects the readpgm function in the pnm.c file when processing PNM image files through the netpbm library. The flaw stems from inadequate input validation and arithmetic handling within the image parsing routine, creating a pathway for remote code execution through maliciously crafted PNM files.
The technical implementation of this vulnerability involves an integer overflow condition that occurs when the readpgm function processes image dimensions specified in PNM files. When attackers provide PNM files containing excessively large width and height values, the integer arithmetic operations fail to properly handle the overflow, resulting in incorrect buffer size calculations. This miscalculation leads to heap-based buffer overflow conditions where the application attempts to write data beyond the allocated memory boundaries, potentially allowing attackers to overwrite critical memory regions and execute arbitrary code.
From an operational perspective, this vulnerability poses significant risks to systems utilizing GOCR for document processing or optical character recognition tasks. The remote exploitation capability means that attackers can potentially compromise systems simply by enticing users to process malicious PNM files, making this a particularly dangerous flaw in environments where automated processing of external image files occurs. The vulnerability affects the core functionality of image parsing within the netpbm library, which serves as a foundation for numerous image processing applications.
The impact of this vulnerability aligns with CWE-190, which categorizes integer overflow conditions that can lead to buffer overflows and arbitrary code execution. This flaw also maps to ATT&CK technique T1059.007 for execution through command and scripting interpreter, as successful exploitation could enable attackers to execute arbitrary commands on vulnerable systems. The vulnerability demonstrates how seemingly benign input validation issues in image processing libraries can escalate into critical security threats, particularly when dealing with untrusted file formats.
Mitigation strategies for this vulnerability include immediate patching of GOCR version 0.40 to address the integer overflow handling in the readpgm function, implementing strict input validation for image dimensions, and deploying network segmentation to limit exposure to potentially malicious file processing. Organizations should also consider implementing sandboxed environments for image processing tasks and regularly updating all image processing libraries to ensure protection against similar vulnerabilities. Additionally, input sanitization measures should be enforced to prevent the processing of PNM files with suspiciously large dimension values, and monitoring systems should be deployed to detect anomalous processing patterns that might indicate exploitation attempts.