CVE-2013-7353 in libpng
Summary
by MITRE
Integer overflow in the png_set_unknown_chunks function in libpng/pngset.c in libpng before 1.5.14beta08 allows context-dependent attackers to cause a denial of service (segmentation fault and crash) via a crafted image, which triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 05/12/2026
The vulnerability identified as CVE-2013-7353 represents a critical integer overflow flaw within the libpng library that affects version 1.5.14beta08 and earlier releases. This issue resides in the png_set_unknown_chunks function located in the pngset.c source file, where improper handling of integer values during image processing creates conditions that can be exploited by malicious actors to disrupt system operations. The vulnerability specifically targets the library's ability to process PNG images containing crafted unknown chunk data, demonstrating how seemingly benign image processing operations can become vectors for system compromise.
The technical implementation of this vulnerability stems from the failure to properly validate and handle integer arithmetic within the png_set_unknown_chunks function. When processing PNG images with specially crafted unknown chunks, the function performs calculations that can exceed the maximum representable value for the integer data type being used. This overflow condition results in incorrect memory allocation sizing, leading to heap-based buffer overflows that can cause segmentation faults and application crashes. The flaw operates within a context-dependent attack model where the malicious input must be carefully constructed to trigger the specific integer overflow scenario, making it particularly insidious as it requires precise control over the input data structure.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable more sophisticated attack vectors. System administrators and developers who rely on libpng for image processing in applications ranging from web servers to desktop software face significant risks when using vulnerable versions of the library. The heap-based buffer overflow can result in unpredictable application behavior, including crashes that may be exploited to bypass security controls or potentially execute arbitrary code. This vulnerability particularly affects systems where PNG image processing is a common operation, such as web applications, content management systems, and image processing pipelines that do not properly validate input data.
Mitigation strategies for CVE-2013-7353 require immediate updates to libpng libraries to versions 1.5.14beta08 or later where the integer overflow has been addressed through proper input validation and arithmetic boundary checking. Organizations should implement comprehensive patch management protocols to ensure all systems utilizing libpng are updated promptly. Additional defensive measures include input validation at multiple layers, implementing strict image processing restrictions, and deploying intrusion detection systems that monitor for abnormal application behavior. The vulnerability aligns with CWE-190, which addresses integer overflow conditions, and represents a classic example of how improper integer handling can lead to memory corruption vulnerabilities. From an ATT&CK framework perspective, this vulnerability maps to techniques involving denial of service and privilege escalation through software exploitation, highlighting the importance of maintaining up-to-date security libraries and implementing robust input validation controls across all application layers.