CVE-2008-3640 in CUPS
Summary
by MITRE
Integer overflow in the WriteProlog function in texttops in CUPS before 1.3.9 allows remote attackers to execute arbitrary code via a crafted PostScript file that triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 08/18/2019
The vulnerability described in CVE-2008-3640 represents a critical security flaw within the Common Unix Printing System CUPS software, specifically affecting versions prior to 1.3.9. This issue resides in the texttops component which handles PostScript file processing for printer communication. The vulnerability manifests as an integer overflow condition within the WriteProlog function, creating a scenario where maliciously crafted PostScript files can trigger unintended memory behavior. The flaw occurs when the system processes certain PostScript constructs that cause integer arithmetic to exceed maximum representable values, leading to unexpected program execution paths.
The technical implementation of this vulnerability involves the manipulation of integer variables during the processing of PostScript prolog sections, which are preamble commands that establish the initial environment for PostScript execution. When an attacker crafts a PostScript file containing specific sequences that cause integer overflow in the WriteProlog function, the system's memory allocation logic becomes compromised. This overflow condition can result in heap-based buffer overflows where adjacent memory regions are overwritten, potentially allowing attackers to manipulate program execution flow. The vulnerability specifically targets the heap memory management system, making it particularly dangerous as it can lead to arbitrary code execution without requiring local privileges.
From an operational perspective, this vulnerability creates significant risks for organizations relying on CUPS-based printing infrastructure. Remote attackers can exploit this flaw by simply sending a specially crafted PostScript document to a vulnerable print server, making the attack surface extremely broad. The impact extends beyond simple privilege escalation as it allows complete system compromise through code execution, potentially leading to data breaches, system takeover, or further network infiltration. The vulnerability affects any system running CUPS versions before 1.3.9 that processes PostScript documents, including networked printers, print servers, and workstation printing systems. This makes it particularly dangerous in enterprise environments where centralized print management is common.
The security implications of this vulnerability align with CWE-190, which describes integer overflow and underflow conditions, and relates to ATT&CK technique T1059.007 for execution through PostScript. Organizations should immediately implement mitigations including updating to CUPS version 1.3.9 or later, which contains patches addressing the integer overflow condition. Network segmentation and access controls should be implemented to limit exposure of print servers to untrusted networks. Additional protective measures include implementing strict PostScript validation filters, monitoring for suspicious print job patterns, and maintaining updated intrusion detection systems that can identify exploitation attempts. The vulnerability demonstrates the critical importance of input validation in print processing systems and highlights the need for robust memory management practices in widely deployed software components.