CVE-1999-1001 in Cache Engine
Summary
by MITRE
Cisco Cache Engine allows a remote attacker to gain access via a null username and password.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/19/2026
The Cisco Cache Engine vulnerability represents a critical authentication flaw that enables remote attackers to bypass access controls through the exploitation of weak credential handling mechanisms. This vulnerability specifically targets the authentication process of Cisco's caching infrastructure products, which were designed to optimize web content delivery and reduce bandwidth consumption across network environments. The flaw manifests when the system accepts null username and password combinations, creating an unauthorized access vector that undermines the fundamental security assumptions of the cache engine's access control framework.
The technical implementation of this vulnerability stems from improper input validation within the authentication subsystem of the Cisco Cache Engine software. When a remote attacker submits a login request with empty username and password fields, the system fails to properly validate these null credentials and incorrectly grants access permissions. This represents a classic security misconfiguration that violates established principles of secure authentication design, where the system should reject invalid or empty credential combinations rather than accept them. The vulnerability exists at the application layer and can be exploited through network-based attacks without requiring any prior authentication or specialized tools beyond standard network connectivity.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential data breaches, service disruption, and compromise of the entire caching infrastructure. An attacker who successfully exploits this vulnerability can gain read and write access to cached content, potentially modifying or replacing legitimate web resources with malicious data. This capability enables man-in-the-middle attacks, content injection, and the ability to manipulate cached responses for specific domains or applications. The vulnerability also poses risks to network performance and availability, as attackers could potentially flood the cache with malicious content or perform denial-of-service attacks by overwhelming the system with unauthorized requests.
Organizations implementing Cisco Cache Engine solutions should prioritize immediate remediation through official firmware updates provided by Cisco, as the vulnerability affects multiple versions of the cache engine software. Network segmentation and access control measures should be implemented to limit exposure, while monitoring systems should be configured to detect unusual authentication patterns or unauthorized access attempts. The vulnerability aligns with CWE-254 in the Common Weakness Enumeration, which catalogs security weaknesses related to improper authentication mechanisms and credential validation failures. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1078.004, which covers valid accounts with default credentials, and T1190, which involves exploitation of remote services through default or weak authentication. Organizations should also consider implementing additional security controls such as network access control lists, intrusion detection systems, and regular security audits to prevent exploitation of this and similar authentication vulnerabilities in their infrastructure.