CVE-2024-7540 in oFono
Summary
by MITRE • 08/06/2024
oFono AT CMGL Command Uninitialized Variable Information Disclosure Vulnerability. This vulnerability allows local attackers to disclose sensitive information on affected installations of oFono. An attacker must first obtain the ability to execute code on the target modem in order to exploit this vulnerability.
The specific flaw exists within the parsing of responses from AT+CMGL commands. The issue results from the lack of proper initialization of memory prior to accessing it. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-23307.
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Analysis
by VulDB Data Team • 04/17/2026
The CVE-2024-7540 vulnerability represents a critical information disclosure flaw within the oFono modem management framework, specifically affecting the handling of AT+CMGL command responses. This vulnerability resides in the cellular modem communication stack where oFono processes SMS message listings through AT commands. The flaw manifests when the application fails to properly initialize memory variables before accessing them during the parsing of SMS message lists, creating a pathway for uninitialized variable access that can expose sensitive data from the system's memory space. The vulnerability is particularly concerning because it operates at the modem communication layer, where it can potentially be exploited by attackers who have already gained code execution capabilities on the target modem. This represents a classic uninitialized variable vulnerability that falls under CWE-457, which describes the use of uninitialized variables in software development practices. The security implications extend beyond simple information disclosure as this vulnerability can serve as a stepping stone for more sophisticated attacks, particularly when combined with other exploitation vectors that may exist within the same system.
The technical exploitation of this vulnerability requires an attacker to first achieve code execution on the target modem itself, typically through a separate initial compromise or privilege escalation. Once this initial foothold is established, the attacker can leverage the uninitialized variable in the AT+CMGL command processing to read memory contents that may contain sensitive information such as authentication credentials, system configuration data, or other confidential information stored in memory buffers. The memory access pattern in question likely involves reading from uninitialized stack or heap variables that contain previously allocated memory contents, which could include remnants of other data structures, passwords, or cryptographic keys. This type of vulnerability demonstrates the importance of proper memory management practices in embedded systems and modem firmware environments where security is paramount. The ATT&CK framework categorizes this as a technique involving privilege escalation and information gathering, where the initial compromise leads to reconnaissance activities that can expose system internals.
The operational impact of this vulnerability extends significantly beyond the immediate information disclosure, as it can provide attackers with valuable insights into the system's memory layout and internal state. This information can be leveraged to enhance subsequent exploitation attempts, potentially enabling attackers to craft more sophisticated attacks that target specific memory regions or exploit other vulnerabilities present in the same system. The vulnerability affects installations where oFono is actively managing modem communications, which includes various mobile device platforms, embedded systems, and IoT devices that rely on this telecommunications framework. The root cause of this issue highlights a fundamental security weakness in the application's memory initialization practices, where developers failed to ensure that all variables are properly initialized before use. This vulnerability represents a significant concern for mobile network infrastructure and devices where modem security is critical, as it can potentially expose sensitive communication data or system internals that could be used to further compromise the device or network. Organizations relying on oFono for modem management should prioritize immediate remediation to address this vulnerability, as it can serve as a foundational weakness that enables more severe exploitation scenarios. The vulnerability's classification as a local information disclosure issue means that the attack vector is limited to scenarios where an attacker already has some level of access to the system, but the potential for escalation remains high when combined with other vulnerabilities in the same attack surface.
Mitigation strategies for CVE-2024-7540 should focus on both immediate remediation and long-term architectural improvements to prevent similar issues. The most effective immediate solution involves applying patches that ensure proper variable initialization before memory access occurs during AT command processing. System administrators should implement monitoring to detect unusual AT command sequences that might indicate exploitation attempts, particularly focusing on command patterns that could trigger the uninitialized variable access. The vulnerability's nature suggests that defensive coding practices should be reinforced throughout the oFono codebase, with particular emphasis on memory management and initialization routines. Organizations should also consider implementing network segmentation and access controls that limit the attack surface available to potential attackers who might attempt to exploit this vulnerability. The remediation process should include thorough code reviews focused on memory management practices and the implementation of static analysis tools that can detect uninitialized variable usage. Additionally, system hardening measures such as enabling address space layout randomization and other memory protection mechanisms can provide additional defense in depth against potential exploitation attempts. Regular security assessments of modem management frameworks should be conducted to identify similar vulnerabilities that may exist in other components of the telecommunications infrastructure.