CVE-2026-42513: e-Sushrut Auth Bypass Vulnerability

CVE-2026-42513 Overview

This vulnerability exists in e-Sushrut due to improper authentication logic that relies on client-side response parameters to determine authentication status. A remote attacker could exploit this vulnerability by intercepting and modifying the server response. Successful exploitation of this vulnerability could allow the attacker to bypass authentication and gain unauthorized access to user accounts on the targeted system.

Critical Impact
Remote attackers can bypass authentication mechanisms and gain unauthorized access to user accounts, potentially compromising sensitive healthcare data managed by the e-Sushrut hospital management system.

Affected Products

e-Sushrut Hospital Management System

Discovery Timeline

2026-04-29 - CVE CVE-2026-42513 published to NVD
2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-42513

Vulnerability Analysis

The vulnerability stems from a fundamental security design flaw where the e-Sushrut application trusts client-side response data to make authentication decisions. This architectural weakness violates the principle of never trusting client-provided data, particularly for security-critical operations like authentication.

The application appears to evaluate authentication success or failure based on parameters returned in server responses that can be intercepted and manipulated by an attacker positioned between the client and server. This type of authentication bypass represents a significant security risk as it allows complete circumvention of access controls without requiring valid credentials.

Healthcare management systems like e-Sushrut typically contain highly sensitive patient information, medical records, and administrative data, making this vulnerability particularly concerning from both a security and regulatory compliance perspective.

Root Cause

The root cause of this vulnerability is the improper implementation of authentication logic that relies on client-side response parameters for determining user authentication status. Instead of validating authentication on the server-side with proper session management and cryptographic verification, the application exposes authentication decision points that can be manipulated through response interception.

Attack Vector

The attack is network-based and requires no user interaction or prior privileges. An attacker can exploit this vulnerability by:

Positioning themselves to intercept network traffic between a legitimate user and the e-Sushrut server (man-in-the-middle position)
Capturing the server's authentication response when a login attempt is made
Modifying the response parameters that indicate authentication status (e.g., changing a failure flag to success, or injecting valid session tokens)
Forwarding the modified response to the client, which then grants access based on the tampered authentication status

This attack methodology requires the ability to intercept and modify HTTP/HTTPS traffic, which may be achieved through various techniques including ARP spoofing, DNS hijacking, or compromised network infrastructure. For detailed technical information, refer to the CERT-IN Security Advisory CIVN-2026-0207.

Detection Methods for CVE-2026-42513

Indicators of Compromise

Unusual login patterns where authentication succeeds despite failed credential validation in server logs
Discrepancies between server-side authentication logs and client-side session establishment
Network traffic anomalies indicating potential man-in-the-middle activity targeting e-Sushrut endpoints
Multiple successful logins from different geographic locations within short timeframes for the same user account

Detection Strategies

Implement network intrusion detection rules to identify potential response tampering attacks against e-Sushrut authentication endpoints
Monitor authentication logs for inconsistencies between credential validation results and session creation events
Deploy application-layer monitoring to detect authentication bypass attempts
Correlate server-side authentication failures with subsequent authorized session activities

Monitoring Recommendations

Enable comprehensive logging of all authentication attempts, including both client-side and server-side validation results
Implement real-time alerting for authentication anomalies such as successful logins following failed credential checks
Monitor network traffic patterns for signs of interception or tampering on authentication-related communications
Establish baseline authentication behavior patterns to identify deviations that may indicate exploitation attempts

How to Mitigate CVE-2026-42513

Immediate Actions Required

Restrict network access to e-Sushrut instances to trusted networks only until a patch is available
Implement additional network-layer authentication controls such as VPN requirements for accessing the application
Enable HTTPS with certificate pinning to prevent man-in-the-middle attacks
Review and audit all user accounts for signs of unauthorized access

Patch Information

Organizations should monitor the CERT-IN Security Advisory CIVN-2026-0207 for official patch availability and remediation guidance from the vendor. Apply security updates as soon as they become available.

Workarounds

Deploy a Web Application Firewall (WAF) configured to inspect and validate authentication responses for tampering
Implement network segmentation to isolate e-Sushrut servers from untrusted network segments
Consider deploying a reverse proxy with response integrity validation capabilities
Enable multi-factor authentication if supported to add an additional authentication layer that cannot be bypassed through response manipulation

bash

# Example: Network access restriction using iptables
# Restrict e-Sushrut access to trusted internal networks only
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.0.0/16 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP