CVE-2026-22114 in Delta UFC500
Summary
by MITRE • 10/30/2026
HTTP basic auth enforces no retry limit or backoff. Combined with the default service password, the keyspace is exhaustible.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability described involves a critical authentication mechanism flaw within an HTTP-based service that relies on Basic Authentication without implementing adequate brute-force protection measures. In standard network security practices, services accepting credentials over unencrypted or even encrypted channels must enforce rate limiting and exponential backoff strategies to mitigate automated credential stuffing and brute-force attacks. The absence of such controls allows an attacker to submit authentication requests at the maximum speed permitted by the underlying transport layer, effectively removing any temporal barrier that would otherwise slow down password guessing attempts. This architectural oversight transforms a potentially secure configuration into one that is trivially exploitable if weak credentials are present.
The severity of this flaw is significantly amplified when combined with default service passwords or other predictable credential sets. Many embedded devices and legacy systems ship with hardcoded usernames and passwords, such as admin/admin or root/root, which are widely documented in public vulnerability databases and hacker forums. Because the HTTP Basic Authentication scheme transmits credentials encoded in Base64 rather than hashed, an attacker can capture these packets and attempt to crack them offline at high speeds if they are intercepted, but more immediately, the lack of server-side retry limits allows for real-time online guessing against the live service. The combination of no rate limiting and a small, known keyspace means that the total number of possible combinations is finite and easily exhaustible within seconds or minutes using automated tools.
From an operational impact perspective, this vulnerability leads to immediate unauthorized access if default credentials are in use. Once authenticated, an attacker gains full control over the affected service, which may expose sensitive data, allow for remote code execution depending on the application logic, or enable lateral movement within a network segment. The lack of backoff mechanisms also means that legitimate users might not be significantly impacted by lockouts, but attackers can continuously probe until success is achieved without triggering alerts based on failed login thresholds in many basic implementations. This creates a persistent risk where the system remains compromised for extended periods if monitoring and intrusion detection systems do not specifically flag high-frequency authentication failures from single sources.
Industry standards such as CWE-307 (Improper Restriction of Excessive Authentication Attempts) directly categorize this flaw, highlighting the failure to limit the number of login attempts or detect abnormal patterns in access requests. Furthermore, within the MITRE ATT&CK framework, this vulnerability facilitates techniques associated with Credential Access and Initial Access, specifically brute-forcing credentials over a network service like HTTP (T1110). The exploitation path is straightforward: an attacker identifies the target endpoint, enumerates common default usernames, and iteratively tests passwords until authentication succeeds. This process requires minimal sophistication but yields high-impact results due to the lack of defensive controls.
Mitigation strategies must address both the immediate configuration weakness and broader architectural defenses. First and foremost, all default service passwords must be changed upon deployment or initial setup, ensuring that unique, complex credentials are used for every instance. Additionally, HTTP Basic Authentication should ideally be deprecated in favor of more secure mechanisms such as OAuth 2.0 or JWT-based token authentication, which do not transmit static secrets with every request and can integrate better with modern identity providers. If Basic Authentication must remain enabled due to legacy constraints, the service implementation must enforce strict rate limiting per source IP address, implement account lockout policies after a small number of failed attempts, and utilize exponential backoff delays that increase progressively with each failure. Deploying these controls ensures that even if default credentials are present or guessed, the attacker cannot exhaustively search the keyspace efficiently, thereby preserving system integrity and availability.