CVE-2016-9634 in Application
Summary
by MITRE
Heap-based buffer overflow in the flx_decode_delta_fli function in gst/flx/gstflxdec.c in the FLIC decoder in GStreamer before 1.10.2 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via the start_line parameter.
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Analysis
by VulDB Data Team • 05/15/2026
The vulnerability identified as CVE-2016-9634 represents a critical heap-based buffer overflow in the GStreamer multimedia framework's FLIC decoder component. This flaw exists within the flx_decode_delta_fli function located in gst/flx/gstflxdec.c, where improper input validation allows maliciously crafted FLIC files to trigger memory corruption. The vulnerability specifically targets the start_line parameter which controls the decoding process of FLIC animation frames, making it accessible through remote exploitation scenarios. The affected GStreamer versions prior to 1.10.2 contain this flaw, exposing systems that process FLIC media files to potential compromise.
The technical implementation of this vulnerability stems from inadequate bounds checking within the FLIC decoder's delta frame processing logic. When the start_line parameter exceeds the allocated buffer boundaries, the function writes data beyond the intended memory allocation, creating a heap overflow condition. This memory corruption can be leveraged by attackers to overwrite adjacent memory locations, potentially leading to arbitrary code execution or system instability. The vulnerability's classification as heap-based indicates that the overflow occurs within dynamically allocated memory regions, making exploitation more complex but also more dangerous due to the unpredictable nature of heap memory layout. According to CWE standards, this maps to CWE-121 Heap-based Buffer Overflow, which is categorized under the broader category of buffer overflow vulnerabilities that occur in heap memory regions.
The operational impact of CVE-2016-9634 extends beyond simple denial of service scenarios to encompass full system compromise potential. Remote attackers can craft malicious FLIC files that, when processed by vulnerable GStreamer installations, will trigger the buffer overflow condition. This vulnerability affects any system or application that utilizes GStreamer's FLIC decoder for media processing, including web browsers, media players, and multimedia applications. The attack surface is particularly broad given GStreamer's widespread adoption across Linux distributions, multimedia applications, and embedded systems. When exploited successfully, the vulnerability can result in arbitrary code execution with the privileges of the affected process, potentially leading to complete system compromise. Additionally, the vulnerability can be exploited in a denial of service attack, causing application crashes and service disruption that can impact availability of multimedia services.
Mitigation strategies for CVE-2016-9634 primarily focus on updating to patched versions of GStreamer where the vulnerability has been addressed through proper bounds checking and input validation. System administrators should immediately upgrade to GStreamer 1.10.2 or later versions that contain the necessary fixes. The patch typically implements proper validation of the start_line parameter before memory allocation and ensures that all buffer operations remain within allocated boundaries. Organizations should also consider implementing network-level protections such as content filtering and sandboxing mechanisms to prevent processing of untrusted FLIC files. Additionally, vulnerability management programs should include regular scanning for outdated GStreamer installations and ensure that all multimedia processing components are kept current with security patches. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving remote code execution through memory corruption and can be classified under T1203 Exploitation for Client Execution when targeting applications that use vulnerable GStreamer components.