CVE-2012-1184 in Asterisk
Summary
by MITRE
Stack-based buffer overflow in the ast_parse_digest function in main/utils.c in Asterisk 1.8.x before 1.8.10.1 and 10.x before 10.2.1 allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a long string in an HTTP Digest Authentication header.
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Analysis
by VulDB Data Team • 09/12/2024
The vulnerability identified as CVE-2012-1184 represents a critical stack-based buffer overflow affecting the Asterisk telephony platform version 1.8.x prior to 1.8.10.1 and 10.x prior to 10.2.1. This flaw exists within the ast_parse_digest function located in the main/utils.c file of the Asterisk source code, demonstrating a classic software security weakness that has significant implications for telephony infrastructure systems. The vulnerability specifically manifests when processing HTTP Digest Authentication headers, making it particularly dangerous for systems that rely on Asterisk for voice communication services. The buffer overflow occurs due to inadequate input validation and bounds checking, allowing attackers to manipulate the stack memory through crafted malicious input strings.
The technical implementation of this vulnerability stems from the function's failure to properly validate the length of input strings before copying them into fixed-size stack buffers. When a remote attacker submits a particularly long string within an HTTP Digest Authentication header, the ast_parse_digest function attempts to store this data without sufficient bounds checking, leading to stack corruption. This type of vulnerability maps directly to CWE-121 Stack-based Buffer Overflow, which is classified under the Common Weakness Enumeration framework as a fundamental memory safety issue. The attack vector is remote and authenticated, meaning that an attacker who can submit HTTP requests to the Asterisk server can trigger this vulnerability. The exploitability of this flaw is enhanced by the fact that HTTP Digest Authentication is commonly used in telephony applications, making the attack surface more accessible.
The operational impact of CVE-2012-1184 extends beyond simple denial of service conditions to potentially enable remote code execution, making it a particularly dangerous vulnerability for enterprise communication systems. When the buffer overflow occurs, it typically results in a crash of the Asterisk process, causing service disruption that can affect voice communication, fax services, and other telephony functions. However, the potential for arbitrary code execution adds a more severe dimension to the threat, as attackers could potentially gain unauthorized control over the affected system. This vulnerability affects organizations that rely on Asterisk for their communication infrastructure, including businesses, telecommunications providers, and service providers who depend on VoIP services. The impact is particularly severe in mission-critical environments where telephony availability is paramount, as the vulnerability could be exploited to disrupt essential communication services.
Mitigation strategies for CVE-2012-1184 should focus on immediate patching of affected Asterisk versions to the patched releases 1.8.10.1 and 10.2.1, which contain the necessary code modifications to prevent the buffer overflow. Organizations should also implement network-level controls such as firewall rules that restrict access to HTTP Digest Authentication endpoints and monitor for unusual authentication header patterns. The vulnerability aligns with ATT&CK technique T1190 for Exploit Public-Facing Application, as it represents an exploitation of a publicly known vulnerability in a widely deployed telephony platform. Additionally, organizations should consider implementing intrusion detection systems that can identify and alert on suspicious authentication header lengths, as well as conducting regular security assessments of their telephony infrastructure to identify similar vulnerabilities. The remediation process should also include comprehensive testing of patched systems to ensure that the vulnerability has been properly addressed without introducing new issues that could affect telephony service availability.