CVE-2026-92921 in admin3
Summary
by MITRE • 09/17/2026
admin3 through 3.0.0 stores account passwords using single-round MD5 with only the username as salt and no key derivation function. Attackers with database access can recover plaintext passwords through offline dictionary or brute-force attacks due to negligible computational effort.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/17/2026
The vulnerability in admin3 versions up to 3.0.0 represents a critical failure in password storage security, rooted in the use of outdated and cryptographically weak hashing algorithms combined with insufficient salting mechanisms. Specifically, the application stores user account passwords using single-round MD5 hashing where the username serves as the sole salt value. This approach fundamentally violates modern cryptographic best practices for credential management because it fails to incorporate a key derivation function such as PBKDF2, bcrypt, scrypt, or Argon2. These functions are designed specifically to introduce computational cost and memory hardness, thereby slowing down attack attempts significantly. By relying on single-round MD5 without any additional salting complexity, the system leaves user credentials exposed to rapid offline cracking if an attacker gains access to the underlying database.
From a technical perspective, the use of MD5 as a password hashing algorithm is inherently flawed due to its speed and known collision vulnerabilities. While MD5 was once considered acceptable for non-security checksums, it has long been deprecated for cryptographic security purposes because modern hardware can compute billions of hashes per second. The decision to use only the username as salt further exacerbates this risk. Salts are intended to be unique, random values generated independently for each user to ensure that identical passwords result in different hash outputs and to prevent pre-computation attacks like rainbow tables. Using a static value derived from the username means that if two users share similar or identical usernames across instances, their password hashes will also match, facilitating cross-instance correlation attacks. Moreover, since the salt is not random, attackers can easily generate targeted dictionaries for specific user bases without needing to reverse-engineer unique salts per account.
The operational impact of this vulnerability is severe, particularly in environments where database access might be compromised through SQL injection, server misconfigurations, or insider threats. An attacker with read-only access to the password store can perform offline brute-force or dictionary attacks against all stored credentials simultaneously. Due to the negligible computational effort required to compute single-round MD5 hashes, large-scale cracking campaigns can be executed in minutes using commodity hardware or cloud computing resources. This effectively renders any complexity requirements for passwords moot if they are not sufficiently long and random, as even moderately complex passwords can be recovered quickly given enough time and processing power. The consequence is a high likelihood of credential compromise leading to unauthorized administrative access, data exfiltration, lateral movement within the network, or complete system takeover depending on the privileges associated with the compromised accounts.
This vulnerability aligns directly with CWE-759: Use of a One-Way Hash without a Salt and CWE-328: Use of Weak Hash. It also maps to MITRE ATT&CK technique T1003.004, which involves OS Credential Dumping via local system methods that could expose these weakly hashed credentials if the database is accessed locally or remotely through exploitation chains. The lack of key derivation functions places this implementation in direct violation of NIST Special Publication 800-63B guidelines for digital identity management, which mandate the use of slow hash functions with appropriate work factors to resist offline attacks.
To mitigate this vulnerability, immediate remediation is required by migrating from MD5 to a modern password hashing algorithm such as Argon2id, bcrypt, or scrypt. These algorithms are designed to be computationally intensive and memory-hard, making brute-force attacks prohibitively expensive for attackers. During the migration process, it is essential to generate unique, cryptographically secure random salts for each user account rather than relying on static values like usernames. If immediate replacement of the hashing mechanism is not feasible due to legacy system constraints, implementing a secondary layer of security such as rate limiting on login attempts and multi-factor authentication can help reduce the risk of successful exploitation while the backend storage is being updated. Additionally, enforcing strong password policies that require high entropy can provide some residual protection against dictionary attacks until the underlying cryptographic weakness is addressed.