CVE-2005-0809 in NotifyLink
Summary
by MITRE
NotifyLink, when configured for client key retrieval, allows remote attackers to obtain AES keys via a direct request to /hwp/get.asp, then uses a weak encryption scheme (fixed byte reordering) to protect the key, which allows remote attackers to obtain the key via a brute force attack.
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Analysis
by VulDB Data Team • 07/17/2024
The vulnerability described in CVE-2005-0809 affects NotifyLink software that is configured for client key retrieval functionality. This particular weakness resides in the web application's handling of cryptographic keys within the /hwp/get.asp endpoint. When a client requests key information through this specific path, the system retrieves and transmits encryption keys without adequate protection mechanisms. The vulnerability represents a critical flaw in the cryptographic implementation where the system employs a weak encryption scheme that relies on fixed byte reordering rather than robust encryption algorithms. This design choice fundamentally undermines the security of the key distribution mechanism, creating an exploitable condition that adversaries can leverage to compromise the entire encryption infrastructure.
The technical flaw stems from the implementation of a weak encryption algorithm that utilizes fixed byte reordering as its primary protection mechanism. This approach fails to provide meaningful cryptographic security since the reordering pattern remains constant and predictable, making it susceptible to brute force attacks. The vulnerability specifically allows remote attackers to obtain AES keys through direct requests to the designated endpoint, bypassing any legitimate authentication or authorization mechanisms that should normally protect such sensitive cryptographic material. The fixed byte reordering scheme essentially provides no real encryption value, as the mathematical properties that make encryption secure are completely absent from this implementation. This weakness directly violates fundamental cryptographic principles and security best practices, as established by industry standards including those referenced in CWE-327, which addresses the use of weak encryption algorithms.
The operational impact of this vulnerability is severe and far-reaching, as it allows remote attackers to compromise the confidentiality of encrypted communications within the NotifyLink system. Once an attacker successfully obtains the AES keys through brute force attacks against the weakly protected endpoint, they gain the ability to decrypt all communications that were previously protected by those keys. This creates a complete breakdown of the cryptographic security model and enables unauthorized access to sensitive data, potentially exposing confidential information, user credentials, or business-critical communications. The vulnerability also aligns with ATT&CK technique T1552.004, which covers unsecured credentials, and demonstrates how weak cryptographic implementations can serve as a primary attack vector for data exfiltration and system compromise. The remote nature of the attack means that adversaries can exploit this weakness from anywhere on the network without requiring physical access or local system privileges.
Mitigation strategies for this vulnerability must address both the immediate exposure and the underlying architectural weakness. The most effective approach involves implementing proper encryption mechanisms that utilize industry-standard algorithms such as AES with random initialization vectors and secure key derivation functions rather than relying on fixed byte reordering. Organizations should immediately disable or remove the vulnerable /hwp/get.asp endpoint if it is not essential for operations, and implement proper access controls and authentication mechanisms for any remaining key distribution functions. Additionally, system administrators should conduct comprehensive security audits to identify other potential weak encryption implementations within the NotifyLink software or related systems. The remediation process should include replacing the fixed byte reordering scheme with properly implemented cryptographic libraries that follow established security standards, ensuring that key management processes incorporate proper entropy and randomization techniques as specified in NIST guidelines and other relevant cryptographic standards.