Source: security-advisories@github.com
Tapir is a private Terraform registry. Tapir versions 0.9.0 and 0.9.1 are facing a critical issue with scope-able Deploykeys where attackers can guess the key to get write access to the registry. User must upgrade to 0.9.2.
Tapir, a private Terraform registry, is vulnerable to a critical flaw allowing attackers to gain write access by guessing Deploykeys. This vulnerability, present in versions 0.9.0 and 0.9.1, could lead to supply chain compromise and unauthorized modification of Terraform configurations. Immediate upgrade to version 0.9.2 is crucial to mitigate this risk.
Step 1: Target Identification: Identify a Tapir registry instance running a vulnerable version (0.9.0 or 0.9.1).
Step 2: Key Enumeration/Guessing: The attacker attempts to guess or enumerate the Deploykey associated with the registry. This could involve brute-forcing, dictionary attacks, or exploiting any known weaknesses in the key generation algorithm.
Step 3: Key Validation: The attacker attempts to use the guessed key to interact with the registry, such as attempting to upload a malicious Terraform module.
Step 4: Write Access Granted: If the guessed key is valid, the attacker gains write access to the registry, allowing them to upload malicious Terraform modules or modify existing ones.
Step 5: Supply Chain Compromise: The attacker's malicious modules are then used by legitimate users of the registry, leading to a supply chain compromise.
The vulnerability stems from a flawed implementation of Deploykey generation or validation within Tapir. The description indicates that the key generation process is susceptible to guessing attacks. This suggests a weakness in the key's entropy, potentially using a predictable algorithm or a limited key space. The root cause likely lies in the lack of robust cryptographic protection for Deploykeys, allowing attackers to brute-force or otherwise deduce the keys necessary to gain unauthorized write access to the registry. The specific function or logic flaw is likely within the key generation, storage, or validation routines related to Deploykeys. The vulnerability is not a buffer overflow or race condition based on the description, but rather a cryptographic weakness.
While no specific APTs are directly linked to this vulnerability at this time, any threat actor targeting infrastructure using Terraform could exploit this. This could include nation-state actors, financially motivated groups, or hacktivists. The potential for supply chain compromise makes this a high-value target. CISA KEV status: Not Applicable (as of this analysis).
Monitor registry access logs for suspicious activity, such as unauthorized uploads or modifications of Terraform modules.
Analyze Terraform module code for unexpected changes or malicious payloads.
Implement intrusion detection systems (IDS) to identify anomalous network traffic associated with registry access.
Review Deploykey management practices and ensure proper key rotation and access control.
Monitor for attempts to access the registry with potentially compromised keys (e.g., failed login attempts).
Check for unexpected changes to the registry's configuration or settings.
Upgrade to Tapir version 0.9.2 or later immediately.
Review and strengthen the Deploykey generation and management process. Implement strong cryptographic key generation algorithms and ensure adequate key entropy.
Implement multi-factor authentication (MFA) for registry access.
Regularly rotate Deploykeys.
Implement robust access controls and least privilege principles.
Monitor registry logs for suspicious activity and implement alerting.
Consider using a dedicated secrets management solution for storing and managing Deploykeys.