CVE-2025-11899: Agentflow Auth Bypass Vulnerability

CVE-2025-11899 Overview

CVE-2025-11899 is a critical Use of Hard-coded Cryptographic Key vulnerability (CWE-321) affecting Agentflow, a workflow automation platform developed by Flowring. This vulnerability allows unauthenticated remote attackers to exploit a fixed cryptographic key embedded in the application to generate valid verification information, thereby gaining unauthorized access to the system as any user.

The attack requires the adversary to first obtain a valid user ID, which can potentially be discovered through enumeration or other reconnaissance techniques. Once a user ID is acquired, attackers can leverage the hard-coded key to forge authentication tokens and impersonate any user within the system.

Critical Impact

Unauthenticated remote attackers can bypass authentication and log in as any user by exploiting the hard-coded cryptographic key, potentially compromising the entire workflow management system.

Affected Products

• Flowring Agentflow (specific version information not available in advisory)

Discovery Timeline

• 2025-10-17 - CVE-2025-11899 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-11899

Vulnerability Analysis

This vulnerability stems from a fundamental cryptographic design flaw where Flowring Agentflow uses a hard-coded cryptographic key for generating authentication verification tokens. Hard-coded keys represent a severe security anti-pattern because once discovered—through reverse engineering, source code exposure, or documentation leaks—the key becomes universally exploitable across all installations of the affected software.

The vulnerability is network-accessible, meaning remote attackers can exploit it without requiring prior authentication or user interaction. However, successful exploitation depends on the attacker's ability to obtain a valid user ID from the target system. This prerequisite slightly increases the attack complexity but does not significantly diminish the overall risk, as user IDs can often be enumerated through other application functionality or obtained through social engineering.

Root Cause

The root cause of CVE-2025-11899 is the use of a hard-coded cryptographic key within the Agentflow application codebase. Instead of implementing proper key management practices—such as generating unique keys per installation, storing keys in secure vaults, or using hardware security modules—the developers embedded a static key directly in the application. This key is then used to create verification tokens that authenticate users to the system.

This design decision violates fundamental cryptographic security principles outlined in CWE-321 (Use of Hard-coded Cryptographic Key), which emphasizes that cryptographic keys should never be embedded in application code or configuration files accessible to attackers.

Attack Vector

The attack vector for CVE-2025-11899 is network-based, allowing remote exploitation. An attacker would typically follow this exploitation path:

1. Reconnaissance: Identify a target Agentflow installation and enumerate or obtain valid user IDs through application functionality, directory services, or social engineering
2. Key Extraction: Extract the hard-coded cryptographic key from the Agentflow application through reverse engineering or analysis of application binaries
3. Token Forgery: Use the extracted key along with a valid user ID to generate legitimate-looking authentication tokens
4. Authentication Bypass: Submit the forged tokens to the application to authenticate as the targeted user
5. Privilege Abuse: Once authenticated, the attacker gains full access to the victim user's account and can perform any actions available to that user

For detailed technical information about this vulnerability, refer to the TW-CERT Security Advisory.

Detection Methods for CVE-2025-11899

Indicators of Compromise

• Unusual authentication patterns, particularly successful logins from unexpected IP addresses or geographic locations
• Multiple successful authentication events for different user accounts originating from the same source IP within a short timeframe
• Authentication tokens with anomalous characteristics or generated outside of normal application flows
• Log entries showing access to sensitive functions without corresponding legitimate user activity

Detection Strategies

• Implement behavioral analysis to detect authentication patterns that deviate from established user baselines
• Monitor for authentication attempts using tokens that appear valid but originate from untrusted networks or unexpected endpoints
• Deploy intrusion detection rules to identify potential token forgery attempts based on timing or request patterns
• Enable comprehensive audit logging for all authentication events and correlate with user activity baselines

Monitoring Recommendations

• Centralize Agentflow authentication logs in a SIEM platform for real-time analysis and alerting
• Configure alerts for impossible travel scenarios where user accounts authenticate from geographically distant locations in short time periods
• Monitor for enumeration activity that may indicate attackers gathering user IDs as a precursor to exploitation
• Implement session monitoring to detect hijacked sessions or anomalous post-authentication behavior

How to Mitigate CVE-2025-11899

Immediate Actions Required

• Contact Flowring support to determine if a patched version of Agentflow is available that addresses this vulnerability
• Implement network segmentation to restrict access to Agentflow instances to trusted networks only
• Enable multi-factor authentication (MFA) where supported to add an additional layer of protection beyond token-based authentication
• Conduct an audit of user accounts to identify any unauthorized access or suspicious activity
• Review and restrict the exposure of user IDs within the application to make enumeration more difficult

Patch Information

Organizations should consult the TW-CERT Security Advisory (English) or the TW-CERT Security Advisory (Chinese) for official remediation guidance from the vendor. Contact Flowring directly for information about security updates that address this hard-coded key vulnerability.

Workarounds

• Deploy a web application firewall (WAF) in front of Agentflow to monitor and filter suspicious authentication requests
• Implement IP allowlisting to restrict access to the Agentflow application from known, trusted network ranges only
• Enable enhanced logging and monitoring to detect potential exploitation attempts while awaiting a vendor patch
• Consider temporarily disabling external access to Agentflow until a security update is available
• Implement additional authentication controls at the network layer such as VPN requirements for remote access

# Example: Network-level access restriction using iptables
# Restrict Agentflow 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