CVE-2025-28128 is a security vulnerability identified in the Mytel Telecom Online Account System version 1.0. The core issue allows attackers to bypass the One-Time Password (OTP) verification process by sending a specially crafted request. OTP verification is a critical security control used to authenticate users and prevent unauthorized access. Bypassing this mechanism effectively nullifies the second factor of authentication, allowing attackers to gain access to user accounts without possessing the legitimate OTP. The vulnerability is categorized under CWE-290, which relates to improper authentication. According to the CVSS 3.1 vector, the vulnerability has a base score of 7.0, indicating a high severity level. The attack vector is network-based (AV:N), requiring high attack complexity (AC:H), no privileges (PR:N), and no user interaction (UI:N). The scope is unchanged (S:U), with a high impact on confidentiality (C:H), low impact on integrity (I:L), and low impact on availability (A:L). This suggests that while the attacker can gain unauthorized access to sensitive information, the ability to modify data or disrupt services is limited. No patches or vendor information are currently available, and there are no known exploits in the wild at the time of publication. The vulnerability was reserved on March 11, 2025, and published on April 25, 2025. The lack of vendor and product details limits the ability to perform targeted mitigation but the technical nature of the flaw indicates a fundamental authentication bypass in the OTP mechanism of the Mytel Telecom system.

For European organizations, the impact of this vulnerability depends largely on the presence and usage of Mytel Telecom Online Account System or similar OTP-based authentication systems. If European telecom providers or their customers use Mytel Telecom services or integrate their systems, unauthorized access to user accounts could lead to significant confidentiality breaches, including exposure of personal data, billing information, and potentially sensitive communication metadata. The high confidentiality impact means attackers could harvest user data or impersonate users for fraudulent activities. Although integrity and availability impacts are low, unauthorized access could facilitate social engineering, financial fraud, or unauthorized service changes. Given the high attack complexity, exploitation may require advanced skills or specific conditions, somewhat limiting widespread exploitation. However, the lack of user interaction and no need for privileges means remote attackers can attempt exploitation directly over the network, increasing risk. European organizations relying on OTP for critical authentication should be aware that this vulnerability undermines the trustworthiness of OTP as a security control, potentially affecting compliance with data protection regulations such as GDPR if personal data is compromised.

1. Immediate mitigation should include implementing additional authentication checks beyond OTP, such as device fingerprinting, behavioral analytics, or risk-based authentication to detect anomalous access attempts. 2. Network-level controls like IP reputation filtering and geo-fencing can reduce exposure to remote attackers. 3. Monitoring and logging of authentication attempts should be enhanced to detect patterns indicative of OTP bypass attempts. 4. If possible, temporarily disable or restrict access to the vulnerable Mytel Telecom Online Account System until a vendor patch or update is available. 5. Conduct a thorough review of all authentication flows to ensure no similar bypasses exist, especially focusing on OTP validation logic. 6. Educate users about potential phishing or social engineering attacks that could exploit compromised accounts. 7. Engage with Mytel Telecom or relevant vendors to obtain patches or security advisories. 8. For organizations integrating Mytel Telecom systems, consider isolating these systems within segmented network zones to limit lateral movement in case of compromise. 9. Implement multi-factor authentication methods that do not solely rely on OTP, such as hardware tokens or biometric factors, to increase security resilience.