CVE-2004-0599 in libpng
Summary
by MITRE
Multiple integer overflows in the (1) png_read_png in pngread.c or (2) png_handle_sPLT functions in pngrutil.c or (3) progressive display image reading capability in libpng 1.2.5 and earlier allow remote attackers to cause a denial of service (application crash) via a malformed PNG image.
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Analysis
by VulDB Data Team • 12/16/2024
The vulnerability described in CVE-2004-0599 represents a critical security flaw affecting libpng versions 1.2.5 and earlier, specifically targeting integer overflow conditions within core image processing functions. This vulnerability stems from insufficient input validation mechanisms in the png_read_png function located in pngread.c, the png_handle_sPLT function in pngrutil.c, and the progressive display image reading capability of the library. These functions process PNG image data without adequate bounds checking on integer values that control memory allocation and buffer operations, creating opportunities for malicious actors to exploit the library through carefully crafted malformed PNG files.
The technical execution of this vulnerability involves attackers constructing specially formatted PNG images that trigger integer overflow conditions when the affected libpng functions attempt to process the image data. When these functions encounter oversized or malformed integer values in the PNG file structure, particularly within color palette definitions or progressive display parameters, the resulting arithmetic overflow causes the application to allocate insufficient memory or attempt invalid memory operations. This leads to application crashes and potential denial of service conditions that can be exploited remotely, as any application using the vulnerable libpng library becomes susceptible to this attack vector.
From an operational perspective, this vulnerability presents significant risks to systems that process PNG images from untrusted sources, including web servers, image processing applications, and content management systems. The impact extends beyond simple service disruption to potentially enable more sophisticated attacks when combined with other vulnerabilities, as the predictable application crashes can be leveraged for information disclosure or even code execution in certain scenarios. The vulnerability affects a wide range of applications that depend on libpng for image handling, making it a critical concern for system administrators and security practitioners managing web applications and image processing pipelines.
The vulnerability aligns with CWE-190, Integer Overflow or Wraparound, which specifically addresses issues where integer arithmetic operations produce results that exceed the maximum value that can be represented by the data type. This classification indicates that the root cause lies in improper handling of integer values during memory allocation calculations within the PNG processing functions. Additionally, the attack pattern corresponds to ATT&CK technique T1203, Exploitation for Client Execution, where adversaries leverage vulnerabilities in image processing libraries to cause application failures and potentially gain unauthorized access to system resources. Organizations should prioritize patching affected systems and implementing input validation measures to prevent exploitation of this vulnerability.
Mitigation strategies include immediate upgrading to libpng versions 1.2.6 or later, which contain fixes for the integer overflow conditions in the affected functions. System administrators should also implement strict input validation for PNG files in applications that process user-uploaded content, including size limitations and format verification before processing. Network-level protections such as web application firewalls can help detect and block malformed PNG requests, while application-level sandboxing can limit the impact if exploitation occurs. Regular security assessments and vulnerability scanning should be conducted to identify systems using outdated libpng versions, and organizations should maintain updated security patches for all image processing libraries in their infrastructure.