CVE-2019-11476 in whoopsie
Summary
by MITRE
An integer overflow in whoopsie before versions 0.2.52.5ubuntu0.1, 0.2.62ubuntu0.1, 0.2.64ubuntu0.1, 0.2.66, results in an out-of-bounds write to a heap allocated buffer when processing large crash dumps. This results in a crash or possible code-execution in the context of the whoopsie process.
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Analysis
by VulDB Data Team • 06/18/2024
The vulnerability identified as CVE-2019-11476 represents a critical integer overflow flaw within the whoopsie crash reporting daemon, a component integral to Ubuntu's desktop environment that handles system crash reports and error diagnostics. This vulnerability affects versions of whoopsie prior to specific security patches released in 2019, making it a significant concern for systems running affected Ubuntu distributions. The flaw manifests during the processing of large crash dumps, where the daemon fails to properly validate integer values before performing memory allocation operations. This particular vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, which is classified as a fundamental weakness in software design that can lead to severe security implications when not properly addressed. The issue is particularly dangerous because it occurs within a system component that typically runs with elevated privileges, creating a potential attack surface that adversaries could exploit to compromise system integrity.
The technical implementation of this vulnerability involves a specific arithmetic operation where an integer value exceeds the maximum representable value for its data type, causing the subsequent heap memory allocation to become invalid. When whoopsie processes a large crash dump, it calculates buffer sizes based on input data that may contain maliciously crafted values. The integer overflow occurs during this calculation phase, resulting in a heap buffer that is allocated with insufficient memory space. This inadequate allocation leads to an out-of-bounds write condition where the program attempts to write data beyond the allocated buffer boundaries, potentially overwriting adjacent memory regions. The vulnerability is particularly concerning because it can be triggered through legitimate crash report processing, meaning that an attacker could potentially craft a specially formatted crash dump to exploit this condition without requiring direct user interaction or elevated privileges beyond those normally available to the whoopsie service.
From an operational perspective, the impact of this vulnerability extends beyond simple system instability to potentially enable remote code execution within the context of the whoopsie process, which typically operates with sufficient privileges to access sensitive system resources. The out-of-bounds write condition creates a memory corruption scenario that can be leveraged by attackers to manipulate program execution flow, potentially leading to arbitrary code execution on the compromised system. This vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, as the compromised whoopsie process may have access to system resources that could be exploited to escalate privileges further. The attack surface is particularly broad since whoopsie is designed to process crash reports from all users and system components, making it a potential target for adversaries who could craft malicious crash reports to trigger the vulnerability. The vulnerability's exploitation could result in complete system compromise, especially when combined with other attack vectors or when the whoopsie process is running with elevated privileges.
Mitigation strategies for CVE-2019-11476 primarily focus on applying the vendor-provided security patches that address the integer overflow condition through proper input validation and boundary checking. System administrators should immediately update their Ubuntu installations to versions 0.2.52.5ubuntu0.1, 0.2.62ubuntu.1, 0.2.64ubuntu0.1, or 0.2.66, which contain the necessary fixes to prevent the integer overflow from occurring. Additionally, implementing proper input validation controls within the whoopsie daemon and other similar crash reporting components can help prevent similar issues from occurring in the future. Network segmentation and privilege separation measures should be considered to limit the potential impact if exploitation were to occur, ensuring that even if an attacker successfully exploits this vulnerability, they cannot easily escalate privileges or access sensitive system resources. The vulnerability also highlights the importance of proper memory management practices and integer overflow protection mechanisms in security-critical software components, particularly those that process untrusted input data from system crash reports. Regular security audits and code reviews focusing on integer arithmetic operations, memory allocation patterns, and buffer handling should be implemented to identify and remediate similar vulnerabilities before they can be exploited by malicious actors.