CVE-2002-1369 in CUPS
Summary
by MITRE
jobs.c in Common Unix Printing System (CUPS) 1.1.14 through 1.1.17 does not properly use the strncat function call when processing the options string, which allows remote attackers to execute arbitrary code via a buffer overflow attack.
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Analysis
by VulDB Data Team • 05/12/2019
The vulnerability identified as CVE-2002-1369 represents a critical buffer overflow flaw within the Common Unix Printing System CUPS software version 1.1.14 through 1.1.17. This issue specifically affects the jobs.c component which handles printing job processing and option string manipulation. The flaw occurs due to improper usage of the strncat function call, which is a standard string concatenation function designed to append characters from one string to another while limiting the number of characters copied. When developers misuse strncat, they can create scenarios where the destination buffer becomes insufficiently sized to accommodate the concatenated result, leading to memory corruption that adversaries can exploit for code execution.
The technical implementation of this vulnerability stems from the improper handling of string operations within the printing job processing pipeline. In the affected CUPS versions, when processing option strings submitted by users or applications, the jobs.c module fails to correctly calculate the available buffer space before performing string concatenation operations. This mismanagement of buffer boundaries creates a scenario where an attacker can craft malicious input that exceeds the allocated buffer size, causing data to overwrite adjacent memory locations. The strncat function itself is designed to prevent buffer overflows by limiting the number of characters appended, but when the developers do not properly account for the null terminator or fail to pre-calculate the total required buffer size, the protection mechanisms become ineffective.
The operational impact of CVE-2002-1369 extends beyond simple code execution capabilities, as it provides attackers with remote exploitation opportunities that can compromise entire printing systems and potentially underlying network infrastructure. This vulnerability allows unauthorized individuals to execute arbitrary code on systems running affected CUPS versions, potentially gaining full control over print servers and their associated resources. The attack vector is particularly concerning because it operates over network connections, meaning that remote attackers can exploit this flaw without requiring physical access to the target systems. Attackers can leverage this vulnerability to install backdoors, modify print job processing behavior, or escalate privileges within the affected systems, making it a significant threat to enterprise printing environments and network security posture.
The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper string handling that violates fundamental security principles. From an ATT&CK framework perspective, this vulnerability maps to techniques involving remote code execution and privilege escalation, as attackers can leverage the buffer overflow to gain elevated system privileges and execute malicious payloads. Organizations using affected CUPS versions face substantial risk of compromise, as the vulnerability can be exploited through normal printing operations without requiring specialized tools or conditions. The attack surface includes any system that accepts print job options from remote sources, making it particularly dangerous in networked environments where print servers are accessible from multiple locations. Security practitioners should consider this vulnerability as part of broader exploitation chains that could lead to complete system compromise, especially when combined with other network-based attack vectors.
Mitigation strategies for CVE-2002-1369 require immediate action including patching affected CUPS installations to versions that properly implement string handling functions, typically version 1.1.18 or later. System administrators should also implement network segmentation to limit access to print servers and consider disabling unnecessary print services when not required. Additional defensive measures include monitoring for suspicious print job submissions and implementing intrusion detection systems that can identify potential exploitation attempts. Organizations should conduct comprehensive vulnerability assessments to identify all systems running affected CUPS versions and establish procedures for regular security updates and patch management. The remediation process should include thorough testing of patched systems to ensure that print functionality remains operational while eliminating the buffer overflow vulnerability.