CVE-2002-1372 in CUPS
Summary
by MITRE
Common Unix Printing System (CUPS) 1.1.14 through 1.1.17 does not properly check the return values of various file and socket operations, which could allow a remote attacker to cause a denial of service (resource exhaustion) by causing file descriptors to be assigned and not released, as demonstrated by fanta.
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Analysis
by VulDB Data Team • 01/16/2025
The Common Unix Printing System CUPS vulnerability identified as CVE-2002-1372 represents a critical resource management flaw that affects versions 1.1.14 through 1.1.17 of the printing system. This vulnerability stems from inadequate error handling mechanisms within the software's file and socket operation implementations, creating a pathway for malicious actors to exploit the system's resource allocation processes. The flaw specifically manifests when the system fails to properly verify return values from essential system calls, leading to improper resource cleanup and eventual system exhaustion.
The technical implementation of this vulnerability involves the failure to validate return codes from file descriptor operations and socket communications within the CUPS daemon. When these operations do not complete successfully, the system should release allocated resources and handle the error condition appropriately. However, in affected versions, the code path does not adequately check for error conditions, allowing file descriptors to remain open and allocated indefinitely. This creates a resource leak scenario where the system's file descriptor table gradually fills up with unreleased handles, ultimately preventing legitimate operations from acquiring new file descriptors.
The operational impact of this vulnerability extends beyond simple denial of service to potentially compromise the entire printing infrastructure of a system. Attackers can exploit this weakness by sending specially crafted print jobs or network requests that trigger the problematic code paths, causing the CUPS service to consume all available file descriptors. Once the system reaches its file descriptor limit, legitimate print jobs fail to process, network connections are disrupted, and the overall system stability is compromised. The demonstration using the fanta exploit illustrates how this vulnerability can be weaponized to systematically exhaust system resources without requiring elevated privileges.
This vulnerability aligns with CWE-404, which addresses improper resource release or unbounded resource consumption, and specifically relates to CWE-772, which covers missing release of resource after effective lifetime. The attack pattern follows the methodology outlined in the MITRE ATT&CK framework under T1499, which covers network denial of service attacks. The exploitation technique represents a classic resource exhaustion attack that can be executed remotely, making it particularly dangerous in networked environments where CUPS services are accessible to untrusted users. Organizations utilizing affected CUPS versions face significant operational risks, as this vulnerability can be exploited to render print services completely unavailable while potentially affecting other system services that depend on proper file descriptor management.
The recommended mitigation strategy involves immediate upgrading to CUPS versions 1.1.18 or later, where the error handling mechanisms have been properly implemented to validate return values and ensure appropriate resource cleanup. Additionally, system administrators should implement monitoring solutions to track file descriptor usage patterns and establish alerting mechanisms for unusual resource consumption. Network segmentation and access controls should be enforced to limit exposure of CUPS services to untrusted networks, while regular security assessments should verify that all print server implementations properly handle system call return values. The vulnerability serves as a critical reminder of the importance of robust error handling and resource management in system-level software components that operate continuously in production environments.