CVE-2018-19502 in Freeware Advanced Audio Decoder
Summary
by MITRE
An issue was discovered in Freeware Advanced Audio Decoder 2 (FAAD2) 2.8.1. There was a heap-based buffer overflow in the function excluded_channels() in libfaad/syntax.c.
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Analysis
by VulDB Data Team • 06/11/2023
The vulnerability identified as CVE-2018-19502 represents a critical heap-based buffer overflow within the Freeware Advanced Audio Decoder 2 version 2.8.1 implementation. This issue specifically manifests within the excluded_channels() function located in the libfaad/syntax.c source file, where improper input validation and memory handling creates exploitable conditions that can lead to arbitrary code execution or system instability. The flaw arises from insufficient bounds checking when processing audio stream data, particularly in scenarios involving malformed or maliciously crafted audio files that contain unexpected channel configuration parameters.
The technical exploitation of this vulnerability occurs when the FAAD2 decoder encounters audio data with excessive or malformed channel exclusion parameters that exceed the allocated buffer boundaries. This heap-based overflow allows attackers to overwrite adjacent memory locations, potentially corrupting program execution flow or injecting malicious code into the decoder process. The vulnerability falls under CWE-121, heap-based buffer overflow, which is classified as a fundamental memory safety issue that has been consistently identified as a primary attack vector in software security assessments. The affected component operates at the core of audio decoding functionality, making it particularly dangerous as it can be triggered through normal media playback operations without requiring special privileges or user interaction beyond opening the malicious file.
The operational impact of this vulnerability extends beyond simple denial of service conditions to encompass potential remote code execution capabilities that could be leveraged by adversaries. Systems utilizing FAAD2 for audio processing, including media players, streaming services, and embedded devices, become vulnerable to exploitation when processing untrusted audio content. The attack surface is particularly broad given FAAD2's widespread adoption in various software applications and operating systems. According to ATT&CK framework categorization, this vulnerability maps to T1203 - Exploitation for Client Execution and T1059 - Command and Scripting Interpreter, as successful exploitation could enable attackers to execute arbitrary commands on compromised systems. The vulnerability's exploitation requires minimal user interaction, making it particularly dangerous in environments where automated media processing occurs.
Mitigation strategies for CVE-2018-19502 should prioritize immediate patching of affected FAAD2 implementations to version 2.8.2 or later, which includes proper bounds checking and input validation within the excluded_channels() function. Organizations should implement comprehensive input sanitization measures, particularly for audio file processing pipelines, and deploy runtime protections such as address space layout randomization and stack canaries to reduce exploitation success rates. Network-based protections including content filtering and media validation can help prevent malicious audio files from reaching vulnerable systems. Security monitoring should focus on detecting abnormal memory allocation patterns and unexpected process behavior during audio decoding operations. Additionally, system administrators should conduct thorough vulnerability assessments of all applications utilizing FAAD2 to identify potential exposure points and ensure proper sandboxing of media processing components to limit potential damage from successful exploitation attempts.