CVE-2018-5147 in Firefox
Summary
by MITRE
The libtremor library has the same flaw as CVE-2018-5146. This library is used by Firefox in place of libvorbis on Android and ARM platforms. This vulnerability affects Firefox ESR < 52.7.2 and Firefox < 59.0.1.
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Analysis
by VulDB Data Team • 11/26/2025
The vulnerability identified as CVE-2018-5147 represents a critical security flaw within the libtremor library that directly impacts Firefox browser functionality on specific mobile platforms. This library serves as a replacement for the standard libvorbis implementation on Android and ARM architectures, creating a unique attack surface that differs from traditional desktop browser environments. The flaw stems from identical vulnerabilities present in CVE-2018-5146, indicating a systemic weakness within the audio decoding components that Firefox employs for multimedia processing. The affected versions include Firefox Extended Support Release versions prior to 52.7.2 and regular Firefox releases before 59.0.1, highlighting the widespread nature of this vulnerability across multiple browser release channels.
The technical implementation of this vulnerability occurs within the audio decoding subsystem of Firefox's multimedia framework where libtremor processes Ogg Vorbis audio files. This library, designed for embedded systems and mobile platforms, contains memory corruption issues that can be exploited through malformed audio data. The flaw manifests when the library fails to properly validate input data during the decoding process, potentially leading to buffer overflows or other memory manipulation errors. Attackers can craft malicious audio files that trigger these memory handling failures, causing unpredictable behavior in the browser's execution environment. The vulnerability's classification aligns with CWE-121, which addresses stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios that are particularly relevant in multimedia processing libraries.
The operational impact of CVE-2018-5147 extends beyond simple browser instability, presenting significant security risks to users of affected Firefox versions on mobile platforms. When exploited, this vulnerability can enable remote code execution attacks where malicious actors control the execution flow of the browser process, potentially leading to complete system compromise. The attack vector is particularly concerning given that mobile browsers are frequently targeted due to the limited security controls present on mobile devices compared to desktop environments. The vulnerability affects users who access web content containing malicious audio files, making it a persistent threat in environments where users encounter untrusted web content. Security researchers have noted that this vulnerability's exploitation can bypass standard security mitigations due to the low-level nature of the memory corruption and the specific ARM architecture optimizations within the libtremor implementation.
Mitigation strategies for this vulnerability require immediate patching of affected Firefox installations to versions that contain fixes for both CVE-2018-5146 and CVE-2018-5147. System administrators and users should prioritize updating to Firefox ESR 52.7.2 or Firefox 59.0.1, which incorporate the necessary code modifications to prevent exploitation of the memory handling flaws. Organizations managing mobile browser deployments should implement automated patch management systems to ensure rapid deployment of security updates across all affected platforms. The ATT&CK framework categorizes this vulnerability under the T1059.007 technique for command and scripting interpreter, as exploitation can lead to arbitrary code execution, and T1203 for exploitation for privilege escalation. Additional defensive measures include implementing content filtering solutions that can detect and block suspicious audio file patterns, along with network monitoring to identify potential exploitation attempts through malformed media content. Security teams should also consider implementing sandboxing mechanisms that limit the potential impact of successful exploitation attempts, particularly in enterprise environments where mobile browser usage is prevalent.