CVE-1999-1074 in Webmin
Summary
by MITRE
Webmin before 0.5 does not restrict the number of invalid passwords that are entered for a valid username, which could allow remote attackers to gain privileges via brute force password cracking.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability described in CVE-1999-1074 represents a critical security flaw in Webmin versions prior to 0.5 that fundamentally undermines authentication security mechanisms. This issue stems from the absence of account lockout or rate limiting controls within the web-based system administration tool, creating an environment where malicious actors can systematically attempt password guesses without restriction. The flaw exists at the authentication layer where the system fails to implement basic protective measures against automated credential guessing attacks, making it particularly dangerous given Webmin's widespread use for remote server administration.
The technical implementation of this vulnerability resides in the authentication subsystem's lack of protective mechanisms against repeated failed login attempts. Webmin versions before 0.5 process each authentication attempt without tracking or limiting subsequent attempts for the same user account, allowing attackers to perform brute force operations with unlimited tries. This design flaw directly violates fundamental security principles outlined in the OWASP Top Ten and aligns with CWE-307, which addresses insufficient account lockout mechanisms. The absence of rate limiting or account lockout functionality creates an attack surface where credential stuffing and password spraying techniques become highly effective against Webmin interfaces.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to systematically compromise administrative accounts through automated brute force methods. Remote attackers can leverage this weakness to gain full administrative privileges on systems running vulnerable Webmin versions, potentially leading to complete system compromise, data exfiltration, and persistent backdoor establishment. The vulnerability's exploitation requires minimal technical skill and can be automated using readily available tools, making it particularly dangerous in environments where Webmin is deployed without additional security controls. This weakness directly maps to ATT&CK technique T1110.003 for Brute Force and T1078.004 for Valid Accounts, as it enables unauthorized access through legitimate authentication paths.
Mitigation strategies for this vulnerability must address both the immediate security gap and implement comprehensive authentication hardening measures. System administrators should immediately upgrade to Webmin version 0.5 or later, which includes proper account lockout mechanisms and rate limiting capabilities. Additional protective measures include implementing network-level restrictions such as firewall rules to limit access to Webmin interfaces, deploying intrusion detection systems to monitor for suspicious authentication patterns, and configuring additional authentication layers such as two-factor authentication. The vulnerability serves as a critical reminder of the importance of implementing proper account lockout mechanisms and rate limiting as fundamental security controls, particularly in administrative interfaces that handle sensitive system functions. Organizations should also consider implementing centralized authentication solutions and monitoring systems to detect and respond to credential-based attacks more effectively.