EUVD-2025-24614

Comprehensive Technical Analysis of EUVD-2025-24614

1. Vulnerability Assessment and Severity Evaluation

Vulnerability Description: The Amazon EMR Secret Agent creates a keytab file containing Kerberos credentials and stores it in the /tmp/ directory. This file can be accessed by users with permissions to this directory, potentially allowing them to decrypt the keys and escalate privileges.

Severity Evaluation: The vulnerability has a base score of 9.0 according to CVSS 4.0, indicating a high severity. The vector string CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H breaks down as follows:

• AV:N - Network vector, indicating the vulnerability is exploitable over the network.
• AC:H - High attack complexity, suggesting that the attack requires specific conditions or knowledge.
• AT:P - Physical attack vector, which is unusual for a network-based vulnerability and might indicate a misclassification.
• PR:L - Low privileges required, meaning an attacker with minimal access can exploit this vulnerability.
• UI:N - No user interaction required.
• VC:H, VI:H, VA:H - High confidentiality, integrity, and availability impact.
• SC:H, SI:H, SA:H - High scope change, integrity, and availability impact.

This high score underscores the critical nature of the vulnerability, particularly in environments where Kerberos authentication is used.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

1. Unauthorized Access: An attacker with access to the /tmp/ directory can read the keytab file.
2. Privilege Escalation: By decrypting the Kerberos credentials, an attacker can escalate privileges to higher levels within the system.
3. Lateral Movement: Once privileges are escalated, the attacker can move laterally within the network, compromising other systems.

Exploitation Methods:

1. File Access: The attacker gains access to the /tmp/ directory and reads the keytab file.
2. Credential Decryption: Using tools or scripts, the attacker decrypts the Kerberos credentials.
3. Privilege Escalation: The attacker uses the decrypted credentials to gain higher privileges.
4. Network Compromise: With elevated privileges, the attacker can compromise other systems within the network.

3. Affected Systems and Software Versions

Affected Systems:

• Amazon EMR versions between 6.10 and 7.4.

Software Versions:

• Amazon EMR 6.10 to 7.4 are vulnerable.
• Amazon EMR version 7.5 and higher are not affected.

4. Recommended Mitigation Strategies

1. Upgrade: Upgrade to Amazon EMR version 7.5 or higher.
2. Patch: For versions between 6.10 and 7.4, apply the provided bootstrap script and RPM files with the fix.
3. Access Control: Restrict access to the /tmp/ directory to only authorized users.
4. Monitoring: Implement monitoring and alerting for unauthorized access attempts to the /tmp/ directory.
5. Regular Audits: Conduct regular security audits to ensure compliance with best practices.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to organizations using Amazon EMR within the European Union, particularly those relying on Kerberos for authentication. The potential for privilege escalation and lateral movement can lead to widespread compromise of sensitive data and systems, impacting confidentiality, integrity, and availability. This underscores the need for robust security practices and timely patch management.

6. Technical Details for Security Professionals

Keytab File Storage:

• The keytab file is stored in the /tmp/ directory, which is typically accessible to multiple users.
• The file contains Kerberos credentials, which are sensitive and should be protected.

Exploitation Steps:

1. Access the /tmp/ Directory: Gain access to the directory where the keytab file is stored.
2. Read the Keytab File: Use standard file reading methods to access the keytab file.
3. Decrypt Credentials: Use tools like kinit or custom scripts to decrypt the Kerberos credentials.
4. Escalate Privileges: Use the decrypted credentials to gain higher privileges within the system.

Mitigation Scripts:

• For versions 6.10 to 7.4, apply the provided bootstrap script and RPM files to mitigate the vulnerability.
• Ensure that the scripts are run with appropriate permissions to apply the fixes effectively.

References:

• Amazon EMR Release Guide
• AWS Security Bulletin

Conclusion: The vulnerability in Amazon EMR versions 6.10 to 7.4 is critical and requires immediate attention. Organizations should prioritize upgrading to version 7.5 or applying the provided patches to mitigate the risk. Implementing strict access controls and monitoring can further enhance security. This vulnerability highlights the importance of timely updates and robust security practices in protecting sensitive systems and data.