CVE-2025-64097
CVE-2025-64097
Weakness (CWE)
CVSS Vector
v4.0- Attack Vector
- Network
- Attack Complexity
- Low
- Attack Requirements
- Present
- Privileges Required
- None
- User Interaction
- None
- Confidentiality (Vulnerable)
- High
- Integrity (Vulnerable)
- High
- Availability (Vulnerable)
- None
- Confidentiality (Subsequent)
- High
- Integrity (Subsequent)
- High
- Availability (Subsequent)
- High
Description
NervesHub is a web service that allows users to manage over-the-air (OTA) firmware updates of devices in the field. A vulnerability present starting in version 1.0.0 and prior to version 2.3.0 allowed attackers to brute-force user API tokens due to the predictable format of previously issued tokens. Tokens included user-identifiable components and were not cryptographically secure, making them susceptible to guessing or enumeration. The vulnerability could have allowed unauthorized access to user accounts or API actions protected by these tokens. A fix is available in version 2.3.0 of NervesHub. This version introduces strong, cryptographically-random tokens using `:crypto.strong_rand_bytes/1`, hashing of tokens before database storage to prevent misuse even if the database is compromised, and context-aware token storage to distinguish between session and API tokens. There are no practical workarounds for this issue other than upgrading. In sensitive environments, as a temporary mitigation, firewalling access to the NervesHub server can help limit exposure until an upgrade is possible.
Comprehensive Technical Analysis of CVE-2025-64097
1. Vulnerability Assessment and Severity Evaluation
CVE ID: CVE-2025-64097 CVSS Score: 9.8
The vulnerability in NervesHub, a web service for managing over-the-air (OTA) firmware updates, involves the predictable format of user API tokens. This flaw allows attackers to brute-force these tokens, potentially leading to unauthorized access to user accounts or API actions. The CVSS score of 9.8 indicates a critical severity due to the potential for significant impact on confidentiality, integrity, and availability.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Brute-Force Attacks: Attackers can exploit the predictable format of API tokens to guess valid tokens through brute-force methods.
- Token Enumeration: Given the user-identifiable components in the tokens, attackers can enumerate tokens to gain unauthorized access.
Exploitation Methods:
- Automated Scripts: Attackers can use automated scripts to generate and test potential tokens.
- Network Sniffing: If tokens are transmitted over unencrypted channels, attackers can capture and analyze them to identify patterns.
3. Affected Systems and Software Versions
Affected Versions:
- NervesHub versions starting from 1.0.0 up to but not including 2.3.0.
Unaffected Versions:
- NervesHub version 2.3.0 and later, which includes the fix for this vulnerability.
4. Recommended Mitigation Strategies
Immediate Mitigation:
- Upgrade: The primary mitigation is to upgrade to NervesHub version 2.3.0 or later, which addresses the vulnerability by introducing strong, cryptographically-random tokens.
- Firewalling: In sensitive environments, temporarily firewalling access to the NervesHub server can limit exposure until an upgrade is possible.
Additional Mitigations:
- Token Management: Ensure that tokens are hashed before database storage to prevent misuse even if the database is compromised.
- Context-Aware Storage: Distinguish between session and API tokens to enhance security.
5. Impact on Cybersecurity Landscape
The vulnerability highlights the critical importance of secure token generation and management in web services. The potential for unauthorized access to user accounts and API actions underscores the need for robust cryptographic practices. This incident serves as a reminder for developers and security professionals to prioritize secure coding practices and regular security audits.
6. Technical Details for Security Professionals
Vulnerability Details:
- Token Format: The predictable format of API tokens included user-identifiable components, making them susceptible to guessing or enumeration.
- Cryptographic Weakness: The tokens were not cryptographically secure, allowing attackers to brute-force them.
Fix Implementation:
- Strong Tokens: Version 2.3.0 introduces strong, cryptographically-random tokens using
:crypto.strong_rand_bytes/1. - Hashing: Tokens are hashed before database storage to prevent misuse.
- Context-Aware Storage: The new version distinguishes between session and API tokens to enhance security.
References:
Conclusion
CVE-2025-64097 is a critical vulnerability affecting NervesHub versions prior to 2.3.0. The predictable format of API tokens allows for brute-force attacks, leading to potential unauthorized access. Upgrading to version 2.3.0, which introduces strong, cryptographically-random tokens and enhanced token management, is the recommended mitigation. This vulnerability underscores the importance of secure token generation and management in maintaining the integrity and security of web services.