CVE-2017-11126 in mpg123
Summary
by MITRE
The III_i_stereo function in libmpg123/layer3.c in mpg123 before 1.25.1 allows remote attackers to cause a denial of service (buffer over-read and application crash) via a crafted audio file that is mishandled in the code for the "block_type != 2" case, a similar issue to CVE-2017-9870.
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Analysis
by VulDB Data Team • 10/24/2019
The vulnerability CVE-2017-11126 represents a critical buffer over-read flaw in the mpg123 media player library that affects versions prior to 1.25.1. This issue resides within the III_i_stereo function located in the libmpg123/layer3.c source file, which is responsible for processing mp3 audio files. The vulnerability manifests when the software encounters specially crafted audio files that exploit improper handling of the "block_type != 2" code path during mp3 frame decoding operations.
The technical implementation of this flaw involves the mp3 decoder's handling of variable length codes within the MPEG audio format specification. When processing audio frames where the block type does not equal 2, the III_i_stereo function fails to properly validate input boundaries before accessing memory regions. This improper bounds checking allows attackers to craft malicious mp3 files that cause the application to read beyond allocated buffer boundaries, resulting in memory corruption and subsequent application crashes. The vulnerability specifically targets the layer 3 decoding process of mp3 files, which is part of the MPEG-1 Audio Layer III standard and commonly used in multimedia applications.
From an operational perspective, this vulnerability creates significant denial of service risks for any application that relies on mpg123 for audio playback. Remote attackers can exploit this flaw by simply providing a maliciously crafted mp3 file to a vulnerable application, causing it to crash without requiring any special privileges or user interaction. The impact extends beyond simple application crashes to potentially affect entire multimedia systems, streaming services, and any software that integrates mpg123 as a dependency. The vulnerability's similarity to CVE-2017-9870 indicates a pattern of buffer over-read issues within the mpg123 library's mp3 decoding implementation, suggesting systematic code quality problems in the handling of edge cases within the audio processing pipeline.
This vulnerability maps to CWE-125, which specifically addresses out-of-bounds read conditions in software implementations. The attack surface aligns with ATT&CK technique T1203, which involves the exploitation of software vulnerabilities to cause denial of service or application crashes. The flaw demonstrates poor input validation practices and inadequate memory boundary checking that are common in audio processing libraries where complex bitstream parsing occurs. Organizations using mpg123 in their applications should immediately implement the patch version 1.25.1 or later, which addresses this vulnerability through proper bounds checking and input validation in the affected function. Additionally, application developers should consider implementing additional input sanitization layers and runtime protections to mitigate potential exploitation of similar vulnerabilities in other audio processing components.