CVE-2002-1363 in libpng
Summary
by MITRE
Portable Network Graphics (PNG) library libpng 1.2.5 and earlier does not correctly calculate offsets, which allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a buffer overflow attack on the row buffers.
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Analysis
by VulDB Data Team • 09/06/2025
The vulnerability identified as CVE-2002-1363 affects the Portable Network Graphics library known as libpng versions 1.2.5 and earlier. This flaw resides within the fundamental image processing capabilities of the library that handles PNG file format parsing and rendering. The issue manifests when the library encounters specially crafted PNG files that exploit miscalculations in offset calculations during row buffer processing, creating a critical security risk that extends beyond simple denial of service to potentially enabling remote code execution.
The technical root cause of this vulnerability stems from improper handling of buffer boundaries within the libpng library's internal processing mechanisms. When parsing PNG files, the library calculates memory offsets to determine where row data should be stored in memory buffers. In affected versions, these calculations fail to properly validate input parameters, leading to situations where maliciously constructed PNG files can cause the library to write data beyond allocated buffer boundaries. This buffer overflow condition occurs because the library does not adequately check the size constraints of incoming data against the allocated memory space, creating opportunities for attackers to manipulate memory layout and execution flow.
The operational impact of this vulnerability presents significant risks to systems relying on libpng for image processing, particularly web servers, image handling applications, and any software that accepts PNG file uploads from untrusted sources. Attackers can leverage this flaw to crash applications through controlled denial of service conditions, but more critically, the buffer overflow can be exploited to execute arbitrary code with the privileges of the affected application. This represents a severe security compromise that could allow remote attackers to gain unauthorized access to systems, escalate privileges, or establish persistent backdoors within networked environments.
The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and relates to ATT&CK technique T1190 for Exploit Public-Facing Application, demonstrating how attackers can leverage application flaws to achieve remote code execution. Organizations using vulnerable versions of libpng face potential compromise of their entire infrastructure, particularly in environments where PNG files are processed without proper validation or sanitization. The risk is amplified in web applications that process user-uploaded content, as these represent prime attack vectors for exploitation. Additionally, the vulnerability affects systems across multiple operating systems and platforms that depend on libpng for image processing, making it a widespread concern for cybersecurity professionals managing diverse technology stacks.
Mitigation strategies include immediate upgrading to libpng version 1.2.6 or later, which contains patches addressing the buffer overflow calculations. Organizations should also implement input validation measures that sanitize PNG file content before processing, employ memory protection mechanisms such as stack canaries, and deploy intrusion detection systems to monitor for exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify systems running outdated versions of the library, while application developers should ensure proper error handling and memory management practices are implemented in their codebases.