CVE-2009-2833 in Mac OS X
Summary
by MITRE
Buffer overflow in the UCCompareTextDefault API in International Components for Unicode in Apple Mac OS X 10.5.8 allows context-dependent attackers to execute arbitrary code or cause a denial of service (application crash) via unspecified vectors.
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Analysis
by VulDB Data Team • 06/02/2025
The vulnerability identified as CVE-2009-2833 represents a critical buffer overflow flaw within the UCCompareTextDefault application programming interface of Apple's International Components for Unicode library, affecting Mac OS X 10.5.8 systems. This buffer overflow occurs within the Unicode text comparison functionality that is fundamental to internationalization support in macOS applications. The vulnerability stems from improper bounds checking during text comparison operations, where the API fails to validate input lengths before processing character data, creating an exploitable condition that can be leveraged by malicious actors.
The technical nature of this vulnerability places it squarely within the CWE-121 category of stack-based buffer overflow conditions, where insufficient validation of input data allows attackers to overwrite adjacent memory locations. The UCCompareTextDefault API processes text strings using Unicode character sets, and when malformed or excessively long input data is passed to this function, the buffer management fails to properly handle the boundary conditions. This flaw exists in the core internationalization libraries that are utilized by numerous system applications and third-party software, amplifying the potential impact across the operating system ecosystem.
From an operational perspective, this vulnerability creates significant security risks for affected systems, as context-dependent attackers can exploit the buffer overflow to either execute arbitrary code with the privileges of the targeted application or cause application crashes that result in denial of service conditions. The attack vectors remain unspecified in the original CVE description, suggesting that the vulnerability may be triggered through various input sources including file processing, network communications, or user interface interactions. The nature of the flaw means that any application utilizing the affected Unicode library could potentially be compromised, making this vulnerability particularly dangerous in enterprise environments where multiple applications depend on these core system components.
The impact extends beyond simple application crashes to encompass potential privilege escalation scenarios, as successful exploitation could allow attackers to execute malicious code within the context of the targeted application. This vulnerability demonstrates the critical importance of proper input validation in system libraries, particularly those handling international character sets where complex encoding schemes can introduce additional attack surfaces. The vulnerability's classification aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation may involve crafting malicious input that triggers the buffer overflow and subsequently executes arbitrary code through the vulnerable API. Mitigation strategies should include immediate system updates from Apple to address the buffer overflow, implementation of input validation controls within applications, and monitoring for suspicious application behavior that may indicate exploitation attempts. Organizations should also consider applying runtime protections such as stack canaries and address space layout randomization to reduce the effectiveness of potential exploitation attempts.