CVE-2012-2415 in Asterisk
Summary
by MITRE
Heap-based buffer overflow in chan_skinny.c in the Skinny channel driver in Asterisk Open Source 1.6.2.x before 1.6.2.24, 1.8.x before 1.8.11.1, and 10.x before 10.3.1 allows remote authenticated users to cause a denial of service or possibly have unspecified other impact via a series of KEYPAD_BUTTON_MESSAGE events.
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Analysis
by VulDB Data Team • 12/22/2024
The CVE-2012-2415 vulnerability represents a critical heap-based buffer overflow within the Skinny channel driver of Asterisk Open Source messaging systems. This flaw exists in the chan_skinny.c component that handles communication with Cisco Skinny Client Control Protocol devices, specifically affecting versions prior to 1.6.2.24, 1.8.11.1, and 10.3.1. The vulnerability manifests when the system processes a sequence of KEYPAD_BUTTON_MESSAGE events, which are standard communication packets used by Cisco IP phones to transmit button press data to the PBX server. These events are typically generated when users interact with telephone keypad interfaces on Cisco IP phones, making this attack vector particularly concerning for enterprise communication systems that rely heavily on such devices.
The technical nature of this vulnerability stems from insufficient input validation and bounds checking within the processing of keypad button messages. When remote authenticated users send malformed or excessively large KEYPAD_BUTTON_MESSAGE events to the affected Asterisk server, the system fails to properly validate the message length and content before copying data into fixed-size heap buffers. This classic buffer overflow condition occurs because the application does not adequately verify that incoming data fits within allocated memory boundaries, allowing attackers to overwrite adjacent memory locations. The heap-based nature of the vulnerability means that memory corruption occurs in the heap rather than the stack, potentially leading to more complex exploitation scenarios including arbitrary code execution or system instability.
The operational impact of CVE-2012-2415 extends beyond simple denial of service conditions, presenting significant risks to enterprise communication infrastructure. Remote authenticated attackers who can establish connections to the Asterisk server can trigger system crashes, restarts, or potentially achieve arbitrary code execution depending on the system configuration and memory layout. This vulnerability directly violates security principles outlined in CWE-121, which addresses heap-based buffer overflow conditions, and aligns with ATT&CK technique T1203 for legitimate credentials and T1499 for network disruption. Organizations using affected Asterisk versions face potential service interruptions that could impact business communications, customer support operations, and overall network reliability. The vulnerability's classification as a remote authenticated attack means that attackers do not need physical access or network-level privileges, but rather must have valid authentication credentials to access the system, making it particularly dangerous in environments where credential management is insufficient.
Mitigation strategies for CVE-2012-2415 focus primarily on immediate patching and system hardening measures. Organizations should upgrade to patched versions of Asterisk that address this vulnerability, specifically versions 1.6.2.24, 1.8.11.1, and 10.3.1 or later. Network segmentation and access controls should be implemented to limit which systems can communicate with the Asterisk server, particularly restricting access to the Skinny protocol ports. Implementing proper input validation and length checking mechanisms within the application layer provides additional defense-in-depth measures. Security monitoring should be enhanced to detect unusual patterns of KEYPAD_BUTTON_MESSAGE events that could indicate exploitation attempts. The vulnerability's characteristics align with security frameworks emphasizing the importance of input validation and secure coding practices as outlined in NIST SP 800-53 and ISO 27001 controls. Regular vulnerability assessments and penetration testing should be conducted to identify similar issues in other communication protocols and applications within the organization's infrastructure.