CVE-2025-26522 Overview
CVE-2025-26522 affects the RupeeWeb trading platform. The vulnerability stems from improper implementation of the One-Time Password (OTP) validation mechanism in certain Application Programming Interface (API) endpoints. An authenticated remote attacker can manipulate API responses to bypass Two-Factor Authentication (2FA) protections on other user accounts.
The weakness is classified under [CWE-302: Authentication Bypass by Assumed-Immutable Data]. CERT-IN published advisory CIVN-2025-0020 documenting the issue.
Critical Impact
An authenticated attacker can bypass 2FA on arbitrary RupeeWeb user accounts, undermining account protection on a financial trading platform where unauthorized access can enable fraudulent trades and theft of funds.
Affected Products
- RupeeWeb trading platform (specific version range not disclosed in advisory)
Discovery Timeline
- 2025-02-14 - CVE-2025-26522 published to the National Vulnerability Database (NVD)
- 2026-04-15 - Last updated in NVD database
Technical Details for CVE-2025-26522
Vulnerability Analysis
The RupeeWeb trading platform exposes API endpoints that perform OTP validation as part of the 2FA workflow. The validation logic relies on client-controlled data within the API response flow rather than authoritative server-side verification. An attacker with valid credentials can intercept and modify API responses to make the application accept a failed or unrelated OTP check as successful.
This behavior matches the [CWE-302] pattern, where the server trusts data the attacker can influence. The defect breaks the authentication boundary that 2FA is intended to enforce. Because the platform is used for securities trading, account takeover carries direct financial consequences.
Root Cause
The root cause is reliance on response-side state for authentication decisions instead of server-authoritative OTP verification. The API does not adequately bind the OTP validation outcome to a signed, server-controlled session state. Sensitive control-flow decisions are influenced by data the client can alter.
Attack Vector
Exploitation requires the attacker to hold valid credentials on the platform, giving them legitimate access to the authenticated API surface. The attacker initiates a 2FA workflow targeting another user account and intercepts the API exchange using a local proxy. By manipulating fields in the server's response, such as success flags or validation status indicators, the attacker tricks the client and downstream server logic into treating the 2FA challenge as satisfied. The attack is conducted over the network and does not require user interaction with the targeted account. Refer to the CERT-IN Vulnerability Note CIVN-2025-0020 for advisory details.
Detection Methods for CVE-2025-26522
Indicators of Compromise
- Repeated 2FA validation requests from a single authenticated session targeting multiple user identifiers.
- API responses on the authentication endpoints with anomalous status codes or success flags that do not correlate with backend OTP records.
- Logins from new devices or geolocations completing without a corresponding successful OTP delivery event in backend logs.
Detection Strategies
- Correlate OTP issuance events with OTP validation events on the server side and alert when validations succeed without a matching issuance record.
- Inspect API gateway logs for response tampering signs, such as clients posting unexpected payloads to validation endpoints or replaying altered response structures.
- Monitor for one authenticated principal triggering 2FA flows associated with multiple distinct account identifiers in a short window.
Monitoring Recommendations
- Enable verbose logging on all authentication and 2FA API endpoints, including request and response bodies and source identifiers.
- Forward authentication telemetry to a centralized analytics platform to baseline normal 2FA success rates and alert on deviations.
- Track account-takeover indicators such as password changes, withdrawal address updates, and trading API key generation that occur shortly after a 2FA event.
How to Mitigate CVE-2025-26522
Immediate Actions Required
- Contact RupeeWeb support to confirm the fixed release and apply the vendor-supplied update across all deployments.
- Force re-authentication for all active sessions and invalidate persistent session tokens issued prior to remediation.
- Review recent authentication and trading activity for indicators of unauthorized 2FA bypass and reset credentials for impacted accounts.
Patch Information
The CERT-IN advisory CIVN-2025-0020 instructs administrators to apply appropriate updates from RupeeWeb. No public CPE entries or patch identifiers are listed in the NVD record. Refer to the CERT-IN Vulnerability Note CIVN-2025-0020 for vendor coordination details.
Workarounds
- Restrict access to the trading platform to known IP ranges or via a Virtual Private Network (VPN) until a fix is confirmed.
- Disable or rate-limit the affected 2FA API endpoints at the upstream Web Application Firewall (WAF) where feasible.
- Require additional out-of-band verification, such as email confirmation, for high-risk operations including withdrawals and API key issuance.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
