CVE-2002-0573 in Solaris
Summary
by MITRE
Format string vulnerability in RPC wall daemon (rpc.rwalld) for Solaris 2.5.1 through 8 allows remote attackers to execute arbitrary code via format strings in a message that is not properly provided to the syslog function when the wall command cannot be executed.
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Analysis
by VulDB Data Team • 09/16/2025
The CVE-2002-0573 vulnerability represents a critical format string flaw in the RPC wall daemon component of Solaris operating systems ranging from version 2.5.1 through 8. This vulnerability specifically affects the rpc.rwalld service which handles remote wall messages, enabling malicious actors to exploit the daemon's improper handling of format string arguments when processing wall commands. The vulnerability stems from the daemon's failure to properly sanitize user-supplied input before passing it to the syslog function, creating an exploitable condition that can be leveraged for arbitrary code execution. This flaw exists at the intersection of improper input validation and insecure programming practices that have been classified under CWE-134, which specifically addresses the use of user-controlled format strings in functions like syslog. The operational impact of this vulnerability is severe as it allows remote attackers to execute arbitrary code with the privileges of the rpc.rwalld process, which typically runs with elevated system privileges. The attack vector involves sending specially crafted messages to the rpc.rwalld service through the RPC mechanism, where the daemon processes these messages without adequate input sanitization. This vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' and T1059, covering 'Command and Scripting Interpreter' as attackers can leverage the format string vulnerability to inject and execute malicious commands. The rpc.rwalld daemon's exposure to network-based attacks makes this vulnerability particularly dangerous as it can be exploited from remote locations without requiring local access or authentication. The root cause of the vulnerability lies in the daemon's reliance on unsafe printf-style functions without proper input validation, creating a classic format string exploitation scenario that has been documented in numerous security advisories and vulnerability assessments. The vulnerability's exploitation potential is amplified by the fact that the wall command functionality is commonly used for system administration purposes, making the rpc.rwalld service a legitimate target for attackers seeking to gain unauthorized access to systems. This particular vulnerability demonstrates the importance of proper input validation and the dangers of insecure coding practices that have been consistently highlighted in security frameworks and industry standards. The flaw represents a fundamental security issue in the Solaris RPC implementation where the system's trust model is violated through improper handling of remote input. Organizations running affected Solaris versions should prioritize immediate patching and remediation efforts as this vulnerability can lead to complete system compromise. The vulnerability also highlights the broader challenge of maintaining secure RPC implementations in enterprise environments where legacy services continue to operate without adequate security updates. Security professionals should consider implementing network segmentation and access controls to limit exposure to this vulnerability while applying vendor-provided patches. The exploitation of this vulnerability requires minimal prerequisites and can be automated, making it particularly attractive to threat actors seeking to compromise Solaris systems. The incident underscores the critical need for regular security assessments and vulnerability management processes that can identify and remediate such flaws before they can be exploited in the wild. This vulnerability serves as a reminder of the importance of secure coding practices and the necessity of thorough input validation in system services that handle remote communication. The lack of proper format string handling in the rpc.rwalld daemon represents a failure in the security design phase and highlights the importance of security testing throughout the software development lifecycle. Organizations should implement comprehensive monitoring and logging of RPC service activity to detect potential exploitation attempts. The vulnerability also demonstrates the ongoing risk posed by legacy system components that may not receive adequate security updates or support from vendors. This issue emphasizes the importance of maintaining up-to-date security patches and implementing robust security monitoring systems to detect and respond to exploitation attempts. The format string vulnerability in rpc.rwalld exemplifies how seemingly minor coding errors can create significant security risks, particularly in services that handle untrusted network input. The exploitation of this vulnerability can lead to complete system compromise and persistent access to affected systems, making it a critical concern for security practitioners. The vulnerability's classification under CWE-134 and its alignment with ATT&CK techniques demonstrates how this flaw fits into broader security frameworks and threat models. Proper mitigation requires not only patching the affected software but also implementing defensive measures such as network access controls and intrusion detection systems to prevent unauthorized access to the vulnerable service. The vulnerability highlights the importance of secure RPC service design and the necessity of implementing proper input validation and sanitization mechanisms in all system components that handle network-based communication.