CVE-2004-0558 in CUPS
Summary
by MITRE
The Internet Printing Protocol (IPP) implementation in CUPS before 1.1.21 allows remote attackers to cause a denial of service (service hang) via a certain UDP packet to the IPP port.
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Analysis
by VulDB Data Team • 07/12/2025
The Internet Printing Protocol IPP implementation in CUPS versions prior to 1.1.21 contains a critical vulnerability that enables remote attackers to execute denial of service attacks through malformed UDP packets. This vulnerability specifically targets the IPP port and exploits a flaw in how the printing system processes incoming UDP traffic, leading to service hang conditions that effectively render the printing service unavailable to legitimate users. The issue stems from inadequate input validation and error handling within the IPP protocol handler, creating an exploitable condition that can be triggered remotely without authentication.
The technical flaw manifests when the CUPS IPP implementation receives specially crafted UDP packets that cause the service to enter an indefinite waiting state or consume excessive system resources. This behavior represents a classic denial of service vulnerability where the attacker can disrupt normal service operations by sending malformed packets to the designated IPP port. The vulnerability is particularly concerning because it operates at the network protocol level, allowing attackers to affect system availability without requiring privileged access or complex exploitation techniques. The flaw falls under the category of improper input validation as defined by CWE-20, where the system fails to properly validate or sanitize incoming network data before processing it.
From an operational impact perspective, this vulnerability creates significant risks for organizations relying on CUPS-based printing services, as it allows attackers to disrupt printing operations across the network. The service hang condition can affect multiple print jobs simultaneously, potentially causing cascading failures in document processing workflows and impacting productivity. Network administrators face the challenge of mitigating this issue while maintaining printing service availability, as the vulnerability can be exploited by anyone with access to the network and knowledge of the IPP port. The attack vector is particularly dangerous because it requires minimal privileges and can be executed remotely, making it an attractive target for malicious actors seeking to disrupt business operations.
Organizations should immediately upgrade to CUPS version 1.1.21 or later, which contains the necessary patches to address this vulnerability. Additionally, network administrators should implement firewall rules to restrict access to the IPP port from untrusted networks and consider monitoring for unusual UDP traffic patterns on port 631. The mitigation strategy should include regular security assessments of printing infrastructure and implementation of network segmentation to limit the potential impact of such attacks. This vulnerability aligns with ATT&CK technique T1499.004 for network denial of service, where adversaries target network infrastructure to disrupt services. The incident highlights the importance of maintaining up-to-date software versions and implementing proper network security controls to prevent exploitation of protocol-level vulnerabilities.