CVE-2017-5842 in GStreamer
Summary
by MITRE
The html_context_handle_element function in gst/subparse/samiparse.c in gst-plugins-base in GStreamer before 1.10.3 allows remote attackers to cause a denial of service (out-of-bounds write) via a crafted SMI file, as demonstrated by OneNote_Manager.smi.
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Analysis
by VulDB Data Team • 03/17/2026
The vulnerability identified as CVE-2017-5842 represents a critical out-of-bounds write flaw within the GStreamer multimedia framework's subparse plugin component. This issue specifically affects the html_context_handle_element function located in the gst/subparse/samiparse.c file within the gst-plugins-base module. The vulnerability manifests when processing specially crafted SMI (Synchronized Multimedia Integration Language) files, which are commonly used for subtitle and caption data in multimedia applications. The flaw enables remote attackers to trigger a denial of service condition through maliciously constructed input files, making it particularly dangerous in networked environments where users might unknowingly encounter compromised media content.
The technical nature of this vulnerability stems from insufficient input validation and boundary checking within the SMI parsing logic. When the html_context_handle_element function processes malformed SMI data, it fails to properly validate array indices or buffer boundaries, leading to memory corruption that results in an out-of-bounds write operation. This type of flaw falls under CWE-787, which specifically addresses out-of-bounds write conditions in software implementations. The vulnerability is particularly concerning because SMI files are frequently used in Office applications and multimedia players, making the attack surface quite broad. The specific demonstration of this vulnerability through OneNote_Manager.smi files shows how legitimate applications that utilize GStreamer for media processing can become vulnerable when handling user-supplied content.
The operational impact of CVE-2017-5842 extends beyond simple denial of service, as it can potentially lead to system instability and application crashes that disrupt user experience. In environments where GStreamer is integrated into enterprise applications, web browsers, or media processing pipelines, this vulnerability could be exploited to cause widespread service disruption. The remote exploitation capability means that attackers do not need physical access to target systems, making it particularly dangerous in web-based applications or content delivery scenarios. This vulnerability aligns with ATT&CK technique T1203, which involves exploiting software vulnerabilities to gain access to systems, and represents a classic example of how multimedia processing components can become attack vectors in modern computing environments.
Mitigation strategies for this vulnerability require immediate patching of affected GStreamer installations to version 1.10.3 or later, which contains the necessary fixes for the boundary checking issues in the SMI parser. System administrators should prioritize updating all GStreamer-dependent applications and ensure that automatic update mechanisms are properly configured. Additionally, implementing input validation controls at network boundaries and application level can help reduce the risk of exploitation. Organizations should also consider deploying network segmentation and access controls to limit the potential impact of successful attacks. The fix implemented in the patched versions addresses the core issue by introducing proper bounds checking and input validation mechanisms that prevent the out-of-bounds write conditions from occurring during SMI file processing. Security monitoring should include detection of unusual memory access patterns and process crashes that might indicate exploitation attempts, particularly in systems handling multimedia content from untrusted sources.