CVE-2021-39997 in EMUI
Summary
by MITRE • 02/10/2022
There is a vulnerability of unstrict input parameter verification in the audio assembly.Successful exploitation of this vulnerability may cause out-of-bounds access.
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Analysis
by VulDB Data Team • 02/14/2022
This vulnerability resides within the audio assembly component of a software system where insufficient input parameter validation creates a pathway for unauthorized memory access patterns. The flaw manifests when the system fails to rigorously verify audio data parameters before processing, allowing malformed or excessively large input values to traverse the validation checks. This weakness directly enables attackers to manipulate audio processing routines through carefully crafted input sequences that exceed expected parameter boundaries. The vulnerability can be categorized under CWE-129 Input Validation and Output Processing, specifically addressing inadequate bounds checking mechanisms. From an operational perspective, this issue represents a critical security gap that could enable arbitrary code execution or system instability during audio processing operations. Attackers leveraging this vulnerability might exploit the out-of-bounds memory access to overwrite critical system variables, inject malicious code into audio processing pipelines, or cause denial of service conditions that disrupt legitimate audio functionality.
The technical implementation of this vulnerability demonstrates a classic buffer over-read condition where audio assembly routines do not properly validate the size or range of incoming audio parameters before attempting to process them. When audio data is fed into the system without proper parameter verification, the assembly code may attempt to access memory locations beyond the allocated buffer boundaries, creating opportunities for information disclosure or execution flow manipulation. This particular weakness aligns with ATT&CK technique T1059 Command and Scripting Interpreter where attackers could potentially leverage the audio processing subsystem to execute unintended code sequences. The vulnerability affects systems that handle audio input processing, particularly those implementing real-time audio assembly routines where parameter validation occurs too late in the processing pipeline.
The operational impact of CVE-2021-39997 extends beyond simple memory corruption scenarios to encompass potential system compromise through indirect exploitation pathways. When audio assembly components process unverified input parameters, attackers can craft malicious audio files or streams that trigger the out-of-bounds access condition during normal system operation. This creates opportunities for privilege escalation attacks where the audio processing subsystem might be leveraged to gain elevated system privileges. The vulnerability's exploitation potential is heightened in environments where audio processing occurs with elevated privileges or where audio data originates from untrusted sources. Organizations implementing audio processing systems should consider the broader security implications of this flaw, particularly in applications handling multimedia content from external sources, as the vulnerability can serve as a foothold for more sophisticated attacks. Security teams must also account for the potential impact on real-time audio streaming applications where such vulnerabilities could be exploited to disrupt service availability or compromise audio data integrity.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation mechanisms within the audio assembly processing pipeline. The primary defense involves adding strict parameter bounds checking before any audio data processing occurs, ensuring that all input parameters fall within expected ranges and sizes. System administrators should deploy input sanitization routines that validate audio parameter values against predefined constraints, including maximum buffer sizes, sample rate limits, and channel count restrictions. Additionally, implementing memory protection mechanisms such as stack canaries, address space layout randomization, and data execution prevention can help mitigate exploitation attempts. Regular security updates and patch management protocols should be enforced to address this vulnerability in affected systems. Organizations should also consider network segmentation and access controls to limit exposure of audio processing components to untrusted input sources. The implementation of automated input validation frameworks and regular code reviews focusing on audio processing routines can help prevent similar vulnerabilities from emerging in future system versions. Security monitoring should include detection of anomalous audio processing patterns that might indicate exploitation attempts.