CVE-2018-25028 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_context can cause a use-after-free.
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Analysis
by VulDB Data Team • 12/30/2021
The vulnerability identified as CVE-2018-25028 resides within the libpulse-binding crate version 1.2.0 and earlier, representing a critical use-after-free flaw that fundamentally compromises memory safety in Rust applications utilizing PulseAudio bindings. This issue specifically affects the get_context function which is responsible for retrieving context handles from the PulseAudio API, creating a scenario where freed memory regions can be accessed after the original allocation has been released. The flaw demonstrates characteristics consistent with CWE-416, which defines use-after-free conditions as a common class of memory safety vulnerabilities occurring when a program continues to reference memory after it has been freed by the system. The vulnerability manifests when the Rust crate fails to properly manage the lifecycle of context objects, allowing attackers to potentially execute arbitrary code or cause application crashes through controlled memory access patterns.
The operational impact of this vulnerability extends beyond simple application instability to encompass potential remote code execution scenarios within applications that depend on PulseAudio for audio processing. When the get_context function returns a context handle that points to freed memory, any subsequent operations on that context may trigger undefined behavior, including memory corruption that could be exploited by malicious actors. This particular flaw aligns with ATT&CK technique T1059.007, which covers the use of scripting languages for exploitation, as the vulnerability could be leveraged through malicious audio applications or services that utilize the affected Rust crate. Applications using this crate in environments where audio services are exposed to untrusted input or network communications face heightened risk, particularly in server environments or desktop applications that process audio streams from external sources.
Mitigation strategies for CVE-2018-25028 require immediate patching of the libpulse-binding crate to version 1.2.1 or later, which implements proper memory management to prevent the use-after-free condition. System administrators and developers should conduct comprehensive code reviews to identify any other instances where the affected crate might be used, particularly in applications handling audio processing or multimedia services. The fix typically involves implementing proper reference counting or smart pointer mechanisms to ensure that context objects remain valid for the duration of their usage, preventing the scenario where freed memory is accessed. Additionally, deployment teams should consider implementing runtime protections such as address space layout randomization and stack canaries to mitigate potential exploitation attempts, while also monitoring for any suspicious behavior patterns that might indicate attempted exploitation of this vulnerability. Organizations should also review their dependency management practices to ensure that all third-party crates are kept up to date with security patches, particularly those handling system-level APIs like audio subsystems that present elevated privilege attack surfaces.