CVE-2002-1789 in newsx
Summary
by MITRE
Format string vulnerability in newsx NNTP client before 1.4.8 allows local users to execute arbitrary code via format string specifiers that are not properly handled in a call to the syslog function.
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Analysis
by VulDB Data Team • 07/03/2024
The vulnerability identified as CVE-2002-1789 represents a critical format string vulnerability within the newsx NNTP client software prior to version 1.4.8. This flaw resides in the client's handling of user-supplied input during syslog function calls, creating a pathway for local attackers to execute arbitrary code on affected systems. The vulnerability specifically manifests when the application fails to properly sanitize format string specifiers, allowing malicious input to be processed through the syslog function without adequate protection mechanisms.
This type of vulnerability falls under the CWE-134 category, which specifically addresses the use of format strings with user-supplied data. The technical implementation flaw occurs at the point where the newsx client processes incoming data and attempts to log it through the syslog function. When format specifiers such as %s, %d, or %x are present in user-provided input and are not properly escaped or validated, the syslog function interprets these specifiers as instructions for formatting additional arguments rather than literal text. This misinterpretation creates opportunities for attackers to manipulate the program's execution flow by injecting carefully crafted format specifiers that can read from memory locations or write to specific addresses.
The operational impact of this vulnerability is significant as it allows local users to escalate privileges and execute arbitrary code with the permissions of the affected process. Since the vulnerability requires local access, attackers must first gain access to a system where the vulnerable newsx client is installed and running. However, once achieved, the privilege escalation potential can be substantial, particularly if the newsx client runs with elevated privileges or if the attacker can leverage the vulnerability to gain access to sensitive system resources. The attack vector is particularly concerning because it operates at the system level through the syslog mechanism, which is a fundamental logging component that applications rely upon for error reporting and system monitoring.
Mitigation strategies for CVE-2002-1789 should focus on immediate patching of the newsx client to version 1.4.8 or later, which contains the necessary fixes for proper format string handling. System administrators should also implement proper input validation and sanitization measures to prevent format specifiers from being passed directly to syslog functions. The remediation approach aligns with ATT&CK technique T1059.007, which covers command and script injection, as attackers may attempt to exploit this vulnerability to execute malicious code through format string manipulation. Additional defensive measures include implementing proper access controls to limit local user access to the newsx client, monitoring syslog entries for suspicious format string patterns, and conducting regular security audits of system logging components. Organizations should also consider implementing application whitelisting policies that restrict execution of vulnerable applications and ensure that all system components are regularly updated to address known vulnerabilities. The vulnerability demonstrates the importance of proper input validation and the dangers of relying on user-supplied data without adequate sanitization before processing through system functions.