CVE-2016-10087 in libpng
Summary
by MITRE
The png_set_text_2 function in libpng 0.71 before 1.0.67, 1.2.x before 1.2.57, 1.4.x before 1.4.20, 1.5.x before 1.5.28, and 1.6.x before 1.6.27 allows context-dependent attackers to cause a NULL pointer dereference vectors involving loading a text chunk into a png structure, removing the text, and then adding another text chunk to the structure.
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Analysis
by VulDB Data Team • 10/27/2022
The vulnerability identified as CVE-2016-10087 represents a critical NULL pointer dereference flaw within the libpng library, a widely used open-source software component for handling png image format operations across numerous applications and systems. This vulnerability specifically affects multiple versions of the libpng library including the 0.71 branch through 1.0.67, 1.2.x versions prior to 1.2.57, 1.4.x versions before 1.4.20, 1.5.x versions before 1.5.28, and 1.6.x versions before 1.6.27. The flaw manifests when the png_set_text_2 function processes text chunks within png image structures, creating a scenario where memory management becomes compromised during text chunk manipulation operations.
The technical execution of this vulnerability involves a specific sequence of operations that manipulate text chunks within png structures. Attackers can exploit this by first loading a text chunk into a png structure, subsequently removing that text chunk from the structure, and then adding another text chunk to the same structure. This particular sequence creates a condition where the library attempts to dereference a NULL pointer during the text chunk handling process, leading to potential application crashes or system instability. The vulnerability operates under context-dependent conditions, meaning it requires specific environmental factors and sequence of operations to be triggered successfully.
The operational impact of this vulnerability extends significantly across the computing landscape since libpng is integrated into countless software applications, web servers, image processing tools, and operating systems. When exploited, this NULL pointer dereference can result in denial of service conditions where applications crash or become unresponsive, potentially allowing attackers to disrupt services or perform resource exhaustion attacks. The vulnerability's exploitation does not typically enable code execution or privilege escalation directly, but the resulting system instability can create opportunities for further attacks or compromise system availability. The widespread adoption of libpng means that numerous applications and platforms could be affected, making this vulnerability particularly concerning from a security perspective.
The vulnerability aligns with CWE-476, which describes NULL Pointer Dereference, and represents a classic example of improper memory management in software libraries. From an attack framework perspective, this vulnerability could be categorized under the ATT&CK technique T1499.004, which involves network denial of service attacks, as the exploitation can lead to service disruption. The flaw demonstrates poor defensive programming practices in memory management where the library fails to properly validate state transitions during text chunk operations. Organizations should implement immediate patch management strategies to upgrade to affected versions of libpng, specifically to versions 1.0.67, 1.2.57, 1.4.20, 1.5.28, and 1.6.27 respectively, as these contain the necessary fixes to prevent the NULL pointer dereference condition. Additionally, input validation and proper error handling mechanisms should be implemented at application layers that utilize libpng to provide additional defense in depth measures against potential exploitation attempts.