CVE-2026-72748 in AVideo
Summary
by MITRE • 08/11/2026
AVideo contains an unauthenticated arbitrary file write vulnerability in the aVideoEncoderChunk.json.php endpoint that allows remote attackers to write up to 4 GB of arbitrary content to the server filesystem via HTTP PUT requests without authentication. Attackers can exhaust disk space causing denial of service, poison the video encoding pipeline, or chain this with local file inclusion to achieve remote code execution.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability exists within the aVideo platform's media processing infrastructure where the aVideoEncoderChunk.json.php endpoint fails to implement proper authentication mechanisms for file upload operations. The flaw represents a critical security gap that allows any remote attacker to perform arbitrary file writes to the server filesystem without requiring valid credentials or access tokens. The endpoint specifically accepts HTTP PUT requests and processes incoming content with minimal validation, enabling attackers to upload files of up to 4 gigabytes in size directly to the target system. This unauthenticated access point creates a severe risk for organizations relying on aVideo for video processing and content management services.
The technical implementation of this vulnerability stems from inadequate input validation and authentication checks within the media encoding pipeline. When an attacker sends a PUT request to the vulnerable endpoint, the system processes the request without verifying the sender's identity or authorization status. This design flaw allows malicious actors to bypass all access controls and directly write content to arbitrary locations on the server filesystem. The 4 gigabyte size limit represents a significant attack surface since it enables attackers to upload large payloads that could include malicious code, system files, or data that could be leveraged for further exploitation. The vulnerability aligns with CWE-285 which addresses insufficient authentication mechanisms and CWE-73 which covers improper neutralization of special elements in file paths.
The operational impact of this vulnerability extends beyond simple denial of service conditions to encompass potential complete system compromise. Attackers can exhaust available disk space through massive file uploads, leading to service disruption and potential system crashes that affect legitimate users. Additionally, the ability to write arbitrary content to the filesystem enables attackers to poison the video encoding pipeline by injecting malicious files that could disrupt processing operations or cause system instability. The most concerning aspect of this vulnerability is its potential for chaining with other exploits such as local file inclusion vulnerabilities, where attackers could upload malicious scripts or binaries that get executed during subsequent video processing operations, thereby achieving remote code execution capabilities. This chain of exploitation follows patterns documented in the ATT&CK framework under technique T1505.003 for server-side includes and T1059 for command and scripting interpreter usage.
Organizations must implement immediate mitigations to address this vulnerability including enforcing strict authentication mechanisms on all file upload endpoints, implementing proper access controls through API keys or session validation, and restricting PUT request handling to authorized users only. Network-level restrictions should be implemented to limit access to the vulnerable endpoint from trusted sources only, while also deploying automated monitoring systems to detect unusual file upload patterns. Regular security audits of application endpoints should verify that no other similar unauthenticated file write operations exist within the system architecture. The platform should be updated with proper input validation and size limitations for all file upload operations, while implementing content-type checks to prevent execution of malicious payloads. System administrators should also configure disk space monitoring to alert on unusual storage consumption patterns that might indicate exploitation attempts, and establish regular backup procedures to ensure rapid recovery from potential compromise scenarios involving this vulnerability.