CVE-2021-26113 in FortiWan
Summary
by MITRE • 04/06/2022
A use of a one-way hash with a predictable salt vulnerability [CWE-760] in FortiWAN before 4.5.9 may allow an attacker who has previously come in possession of the password file to potentially guess passwords therein stored.
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Analysis
by VulDB Data Team • 04/08/2022
The vulnerability identified as CVE-2021-26113 represents a critical weakness in FortiWAN's password hashing implementation that directly relates to CWE-760, which specifically addresses the use of one-way hash functions with predictable salt values. This flaw exists in FortiWAN versions prior to 4.5.9 and creates a significant security risk for organizations relying on this network management platform. The vulnerability stems from the implementation of password hashing algorithms that do not properly randomize salt values, making the system susceptible to various password recovery attacks.
The technical flaw manifests when the system employs a one-way hash function such as MD5 or SHA-1 without adequately randomizing the salt component that should be unique for each password. When salts are predictable or reused, attackers can employ precomputed rainbow table attacks or brute force methods more effectively than they would against properly salted hashes. This vulnerability becomes particularly dangerous when attackers have already obtained access to the password file, as they can then leverage the predictable salt to significantly reduce the computational complexity required to reverse engineer stored passwords. The predictable nature of the salt means that attackers can precompute hash values for common passwords using the known salt, dramatically accelerating the password recovery process.
From an operational impact perspective, this vulnerability compromises the fundamental security of user authentication within FortiWAN environments, potentially allowing unauthorized access to network management systems and sensitive infrastructure controls. The attack surface expands significantly when considering that FortiWAN serves as a critical network management platform for enterprise environments, meaning compromised credentials could lead to complete network infiltration. Organizations using affected versions face the risk of credential compromise that could result in data breaches, unauthorized network modifications, and potential lateral movement within their infrastructure. The vulnerability also impacts compliance with various security frameworks that require proper password storage mechanisms, potentially leading to regulatory violations and audit failures.
Mitigation strategies for this vulnerability must include immediate upgrade to FortiWAN version 4.5.9 or later, which addresses the predictable salt implementation in password hashing. Organizations should also implement comprehensive password policy enforcement including mandatory password changes for all users, implementation of multi-factor authentication where possible, and regular security assessments of authentication systems. Security teams should conduct thorough audits of password files and implement proper key derivation functions such as PBKDF2, bcrypt, or scrypt that incorporate properly randomized salts and sufficient computational cost to resist brute force attacks. Additionally, organizations should establish monitoring procedures to detect unauthorized access attempts and implement network segmentation to limit the potential impact of credential compromise. The remediation process should include rehashing existing password files with properly randomized salts and ensuring that all future password storage operations adhere to industry standards such as those defined in the OWASP Password Storage Cheat Sheet and NIST Special Publication 800-63B for digital identity management.