CVE-2014-0044 in Mumble
Summary
by MITRE
The opus_packet_get_samples_per_frame function in client in Mumble 1.2.4 and the 1.2.3 pre-release snapshots allows remote attackers to cause a denial of service (crash) via a crafted length prefix value, which triggers a NULL pointer dereference or a heap-based buffer over-read (aka "out-of-bounds array access").
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Analysis
by VulDB Data Team • 02/01/2022
The vulnerability identified as CVE-2014-0044 resides within the Mumble client application version 1.2.4 and its pre-release snapshots, specifically affecting the opus_packet_get_samples_per_frame function. This flaw represents a critical security issue that demonstrates poor input validation mechanisms within the audio processing pipeline of the communication software. The vulnerability manifests when the application processes crafted audio packets containing malformed length prefix values, creating a scenario where the software fails to properly validate incoming data before attempting to process it.
The technical implementation of this vulnerability stems from insufficient bounds checking within the opus_packet_get_samples_per_frame function, which is responsible for determining the number of samples per frame in Opus audio packets. When maliciously crafted length prefixes are received, the function attempts to access memory locations that have not been properly validated or allocated, resulting in either a NULL pointer dereference or a heap-based buffer over-read condition. This type of vulnerability falls under the CWE-125 weakness category, specifically addressing out-of-bounds read conditions that occur when a program accesses memory beyond the allocated buffer boundaries. The flaw operates at the intersection of memory safety and input validation, where the application fails to properly sanitize incoming packet data before processing.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides remote attackers with the capability to crash the Mumble client application consistently. This creates a persistent threat vector that can be exploited without requiring authentication or special privileges, making it particularly dangerous in environments where secure communication is critical. The vulnerability affects the core audio processing functionality of the application, potentially disrupting real-time voice communication for all users in affected sessions. According to ATT&CK framework categorization, this represents a privilege escalation technique through application layer exploitation, specifically targeting the application's input validation controls. The crash condition can be reliably reproduced by sending malformed packets, making it a predictable and exploitable weakness that could be leveraged for more sophisticated attacks.
Mitigation strategies for CVE-2014-0044 should focus on immediate patching of the affected Mumble client versions, with the release of version 1.2.5 addressing the input validation issues. System administrators should implement network monitoring to detect malformed audio packets that could indicate exploitation attempts, while also considering network segmentation to limit potential impact. The fix requires robust input validation that properly checks length prefixes against expected ranges and implements proper bounds checking before any memory access operations. Additionally, deploying intrusion detection systems that can identify unusual packet patterns and implementing regular security updates for all communication software components will help prevent similar vulnerabilities from being exploited in the future. Organizations should also consider implementing application whitelisting policies to restrict execution of unauthorized software versions and establish incident response procedures specifically addressing denial of service attacks targeting communication applications.