CVE-2018-25027 in libpulse-binding Crate
Summary
by MITRE • 12/27/2021
An issue was discovered in the libpulse-binding crate before 1.2.1 for Rust. get_format_info can cause a use-after-free.
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Analysis
by VulDB Data Team • 12/30/2021
The vulnerability identified as CVE-2018-25027 resides within the libpulse-binding crate version 1.2.0 and earlier, representing a critical memory safety issue that affects Rust applications leveraging pulse audio bindings. This flaw manifests through the get_format_info function which operates within the context of audio device enumeration and format negotiation for pulse audio systems. The issue arises from improper memory management practices where the function returns a reference to memory that has already been deallocated, creating a use-after-free condition that can be exploited by malicious actors to execute arbitrary code or cause system instability. The vulnerability impacts any Rust application that utilizes the libpulse-binding crate for audio processing, particularly those involving multimedia applications, audio streaming services, or system-level audio management tools.
The technical root cause of this vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software systems. The flaw occurs when the get_format_info function handles memory allocation and deallocation for audio format information structures, where the underlying memory is freed before all references to it are properly invalidated. This creates a window where subsequent access to the freed memory location can result in unpredictable behavior, data corruption, or potential code execution. The vulnerability is particularly concerning in the context of audio processing applications where memory corruption can lead to privilege escalation or denial of service conditions, as the audio subsystem often operates with elevated privileges in many operating systems. The issue demonstrates poor resource management practices that violate fundamental security principles of memory safety.
From an operational standpoint, this vulnerability presents significant risks to systems running Rust applications that depend on pulse audio for audio functionality. Attackers could potentially exploit this condition by crafting malicious audio streams or manipulating audio device configurations to trigger the use-after-free scenario. The impact extends beyond simple application crashes to include potential privilege escalation attacks where malicious code could be executed with the privileges of the audio subsystem process. Systems utilizing this crate in production environments, including servers, desktop applications, and embedded systems with audio capabilities, face exposure to this vulnerability. The exploitation potential is heightened in environments where audio processing occurs with untrusted input, such as multimedia applications handling user-uploaded content or network-based audio streaming services.
Mitigation strategies for CVE-2018-25027 primarily involve upgrading to libpulse-binding version 1.2.1 or later, which contains the necessary memory management fixes to prevent the use-after-free condition. System administrators should prioritize patching affected applications and dependencies to eliminate exposure to this vulnerability. Additionally, implementing runtime protections such as address space layout randomization and stack canaries can provide additional defense-in-depth measures. Security monitoring should include detection of unusual audio processing patterns that might indicate exploitation attempts. Organizations should also consider implementing application whitelisting and privilege separation for audio processing components to limit the potential impact of successful exploitation attempts. The fix addresses the underlying memory management issues by ensuring proper reference counting and memory lifecycle management within the audio format information handling code, aligning with ATT&CK technique T1068 which covers privilege escalation through memory corruption vulnerabilities.