CVE-2017-11546 in TiMidity++
Summary
by MITRE
The insert_note_steps function in readmidi.c in TiMidity++ 2.14.0 allows remote attackers to cause a denial of service (divide-by-zero error and application crash) via a crafted mid file. NOTE: a crash might be relevant when using the --background option.
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Analysis
by VulDB Data Team • 11/02/2019
The vulnerability identified as CVE-2017-11546 resides within the TiMidity++ 2.14.0 multimedia application, specifically in the readmidi.c source file where the insert_note_steps function processes midi file data. This flaw represents a classic divide-by-zero error condition that occurs when processing malformed midi files, creating a critical security risk for systems that utilize TiMidity++ for audio processing. The vulnerability is particularly concerning because it can be exploited remotely through crafted midi files, making it accessible to attackers who may not require local system access. The issue manifests when the application encounters specific malformed midi data structures that cause arithmetic operations to attempt division by zero, leading to immediate application termination and denial of service conditions.
The technical implementation of this vulnerability stems from inadequate input validation within the midi file parsing logic of TiMidity++. When the insert_note_steps function processes note data from midi files, it fails to properly validate certain numerical values that should never be zero during normal operation. This validation gap allows attackers to craft midi files containing specific parameters that force the application into a divide-by-zero state, which is a well-documented software flaw categorized under CWE-369. The flaw operates at the application layer and can be triggered without requiring special privileges, making it particularly dangerous in environments where TiMidity++ is used to process untrusted midi data from external sources. The vulnerability demonstrates poor error handling practices and insufficient boundary checking within the midi parsing subsystem.
From an operational impact perspective, this vulnerability creates significant disruption for systems that rely on TiMidity++ for audio processing, particularly those configured with the --background option as noted in the vulnerability description. When exploited, the divide-by-zero error causes immediate application crashes, effectively denying service to legitimate users who depend on the midi processing capabilities. The impact extends beyond simple service interruption as it can affect automated systems, media servers, and applications that integrate TiMidity++ as a component for audio synthesis. Systems running with the --background option are especially vulnerable because the application may crash during background processing, potentially leading to complete system instability or requiring manual intervention to restore functionality. This vulnerability aligns with ATT&CK technique T1499.004 for Denial of Service, specifically targeting application availability through exploitation of software flaws.
The remediation approach for CVE-2017-11546 requires immediate patching of the TiMidity++ application to version 2.15.0 or later, which contains the necessary fixes for the divide-by-zero error condition. System administrators should implement input validation measures to prevent processing of untrusted midi files, particularly in environments where TiMidity++ is exposed to external users or automated processing pipelines. The fix typically involves adding proper boundary checks and error handling around the mathematical operations that previously caused the divide-by-zero condition. Organizations should also consider implementing network segmentation and access controls to limit exposure to potentially malicious midi files, while monitoring for unusual application behavior that might indicate exploitation attempts. Additionally, regular security assessments of multimedia processing applications should be conducted to identify similar input validation vulnerabilities that could lead to similar denial of service conditions.