CVE-2002-0525 in INN
Summary
by MITRE
Format string vulnerabilities in (1) inews or (2) rnews for INN 2.2.3 and earlier allow local users and remote malicious NNTP servers to gain privileges via format string specifiers in NTTP responses.
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Analysis
by VulDB Data Team • 11/24/2024
The vulnerability described in CVE-2002-0525 represents a critical format string vulnerability affecting the INN (InterNetNews) software suite, specifically impacting inews and rnews utilities in versions 2.2.3 and earlier. This flaw exists within the network news transfer protocol implementation where the software fails to properly validate format string arguments when processing NNTP responses from remote servers. The vulnerability stems from improper input handling in the printf family of functions, where user-supplied data from network responses is directly used as format strings without adequate sanitization. This creates a dangerous condition where malicious NNTP servers can inject format string specifiers that cause the vulnerable software to read from arbitrary memory locations or execute arbitrary code.
The technical exploitation of this vulnerability occurs when a malicious NNTP server sends specially crafted responses containing format string specifiers to either inews or rnews utilities. These utilities, designed to process news articles and messages, directly use the received data as format arguments in printf calls without proper validation. When the software attempts to process these malformed responses, the format string specifiers can cause the program to dereference memory addresses, leading to information disclosure, application crashes, or potentially arbitrary code execution. The vulnerability affects both local users who might manipulate input data and remote malicious NNTP servers that can exploit this weakness over the network. This represents a classic CWE-134 vulnerability category, where format string arguments are derived from external inputs and not properly validated or sanitized before use.
The operational impact of CVE-2002-0525 extends beyond simple privilege escalation to encompass complete system compromise when exploited by malicious actors. Local users with access to the system can leverage this vulnerability to gain elevated privileges, while remote attackers can exploit it through compromised NNTP servers to execute arbitrary code on vulnerable systems. The vulnerability affects systems running INN versions 2.2.3 and earlier, which were widely deployed in news server configurations during that era. When successfully exploited, the vulnerability can lead to unauthorized access to system resources, data exfiltration, and potential establishment of persistent backdoors. The attack vector involves standard NNTP protocol communication, making it particularly dangerous as it operates within normal network traffic patterns and can be difficult to detect through traditional network monitoring.
Mitigation strategies for this vulnerability require immediate software updates to patched versions of INN that properly validate format string arguments. System administrators should implement network segmentation to limit access to NNTP services and consider disabling unnecessary NNTP functionality where possible. The vulnerability aligns with ATT&CK technique T1059.007 for command and script interpreter, as exploitation may involve executing malicious code through compromised news server processes. Additionally, implementing proper input validation and using secure coding practices such as employing snprintf instead of sprintf functions can prevent similar vulnerabilities in the future. Organizations should also consider deploying network intrusion detection systems capable of identifying malformed NNTP responses that may indicate exploitation attempts. The vulnerability demonstrates the importance of proper error handling and input validation in network services, particularly those handling external data from untrusted sources, as outlined in various secure coding guidelines and best practices for network security.