CVE-2026-50210 in Connect M6E 5G Portable WiFi Router
Summary
by MITRE • 06/04/2026
The device encrypts data using AES-CBC with static zero-filled Initialization Vectors (IVs), making it susceptible to replay attacks and known-plaintext decryption.
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Analysis
by VulDB Data Team • 06/04/2026
This vulnerability represents a critical cryptographic flaw that fundamentally undermines the security assurances provided by encryption mechanisms. The device employs AES-CBC encryption with static zero-filled initialization vectors, which creates a deterministic encryption environment where identical plaintext blocks always produce identical ciphertext blocks. This weakness directly violates fundamental cryptographic principles and creates multiple attack vectors that can be exploited by adversaries. The use of static IVs eliminates the randomness essential for secure encryption, rendering the system vulnerable to various well-documented cryptographic attacks including ciphertext-only attacks and known-plaintext attacks. This implementation pattern falls squarely under CWE-327, which specifically addresses the use of weak encryption algorithms and improper implementation of cryptographic functions.
The operational impact of this vulnerability extends far beyond simple data confidentiality breaches. Attackers can exploit the predictable encryption patterns to perform replay attacks where previously captured ciphertext can be reused to execute malicious actions within the system. This is particularly dangerous in networked environments where the same data might be transmitted multiple times, allowing attackers to intercept and reuse encrypted communications. The static IVs also enable known-plaintext attacks where an attacker can use previously observed plaintext-ciphertext pairs to deduce encryption keys or decrypt other communications. From an attacker's perspective, this vulnerability aligns with several ATT&CK techniques including T1566 for credential access through encryption bypass and T1071 for application layer protocol usage. The predictable nature of the encryption makes it easier for adversaries to perform pattern analysis and correlation attacks that would otherwise be impossible with properly randomized IVs.
The technical implications of this flaw extend to the core security architecture of the device, as it fundamentally compromises the confidentiality guarantees that users expect from encryption. When IVs are static and predictable, the encryption system loses its ability to provide semantic security, meaning that even if the encryption algorithm itself is strong, the implementation renders it ineffective. This vulnerability also creates opportunities for advanced persistent threat actors to perform long-term surveillance and data exfiltration campaigns, as the static nature of the IVs allows for systematic analysis of encrypted communications over time. The weakness creates a persistent backdoor that remains exploitable regardless of key rotation or other security updates, making it particularly concerning for systems that handle sensitive or classified information. Organizations implementing such flawed encryption mechanisms should consider immediate remediation through proper IV generation, implementation of authenticated encryption modes, and comprehensive security assessments to identify other potential cryptographic weaknesses. The vulnerability also highlights the importance of following established security standards such as NIST SP 800-38A for proper block cipher modes of operation and the broader cryptographic security framework that requires proper IV management and randomization for secure encryption implementations.