CVE-2025-68701: Jervis Library Cryptographic Vulnerability

CVE-2025-68701 Overview

CVE-2025-68701 is a cryptographic vulnerability affecting Jervis, a library for Job DSL plugin scripts and shared Jenkins pipeline libraries. Prior to version 2.2, Jervis uses deterministic AES IV (Initialization Vector) derivation from a passphrase, which represents a significant weakness in the cryptographic implementation that could allow attackers to compromise encrypted data.

Critical Impact

The use of deterministic IV derivation in AES encryption weakens the cryptographic protection of sensitive data, potentially allowing attackers to identify patterns in encrypted content and derive plaintext information from ciphertext.

Affected Products

• Jervis library versions prior to 2.2
• Jenkins environments utilizing Jervis for Job DSL plugin scripts
• Jenkins pipeline configurations using Jervis shared libraries

Discovery Timeline

• 2026-01-13 - CVE CVE-2025-68701 published to NVD
• 2026-01-13 - Last updated in NVD database

Technical Details for CVE-2025-68701

Vulnerability Analysis

This vulnerability falls under CWE-327 (Use of a Broken or Risky Cryptographic Algorithm). The core issue stems from how Jervis handles AES encryption initialization vectors. In proper AES-CBC or similar block cipher modes, the IV must be unpredictable and unique for each encryption operation to ensure semantic security. When the IV is derived deterministically from a passphrase, the same plaintext encrypted with the same passphrase will always produce identical ciphertext.

This behavior enables several attack scenarios. An adversary who can observe multiple ciphertexts can identify when the same plaintext has been encrypted, breaking the confidentiality guarantees that encryption is supposed to provide. In a Jenkins environment where Jervis manages sensitive configuration data, credentials, or secrets, this weakness could expose organizational security.

Root Cause

The root cause is the deterministic derivation of the AES Initialization Vector from a user-supplied passphrase. Instead of generating a cryptographically random IV for each encryption operation, the implementation derives the IV using a predictable function of the passphrase. This approach violates fundamental cryptographic principles that require IVs to be unique and unpredictable across encryption operations.

Attack Vector

The vulnerability is exploitable over the network without requiring any privileges or user interaction. An attacker with access to encrypted data produced by Jervis can:

1. Collect multiple ciphertexts encrypted under the same passphrase
2. Identify identical ciphertext blocks that indicate identical plaintext
3. Perform known-plaintext attacks if any encrypted content is known or guessable
4. Potentially recover sensitive information such as credentials or configuration secrets

The attack requires the ability to intercept or access encrypted data, which may be possible through compromised Jenkins build logs, configuration exports, or network traffic analysis.

Detection Methods for CVE-2025-68701

Indicators of Compromise

• Presence of Jervis library versions prior to 2.2 in Jenkins installations
• Encrypted configuration data or secrets that may have been exposed
• Unusual access patterns to Jenkins configuration or credential stores
• Evidence of data exfiltration from Jenkins environments

Detection Strategies

• Audit Jenkins installations for Jervis library versions using dependency scanning tools
• Review Jenkins plugin configurations to identify usage of Jervis shared libraries
• Implement file integrity monitoring on Jenkins configuration directories
• Monitor for unauthorized access to encrypted credential stores

Monitoring Recommendations

• Enable comprehensive logging for Jenkins configuration changes and credential access
• Implement network monitoring for unusual data transfers from Jenkins servers
• Configure alerts for changes to Jenkins pipeline library configurations
• Establish baseline behavior analysis for Jenkins API and build activity

How to Mitigate CVE-2025-68701

Immediate Actions Required

• Upgrade Jervis library to version 2.2 or later immediately
• Rotate all secrets and credentials that were encrypted using vulnerable versions
• Audit systems for potential exposure of encrypted data
• Review Jenkins build logs and configuration exports for sensitive data leakage

Patch Information

The vulnerability is fixed in Jervis version 2.2. The fix implements proper cryptographic IV handling with random IV generation for each encryption operation. Organizations should update to the latest version by modifying their Jenkins shared library configurations to reference the patched version.

For detailed patch information, refer to the GitHub Commit Change which addresses this vulnerability. Additional context is available in the GitHub Security Advisory.

Workarounds

• If immediate upgrade is not possible, consider temporarily disabling Jervis encryption features and using alternative secret management solutions
• Implement additional encryption layers using properly configured external tools
• Restrict network access to Jenkins instances to limit exposure of encrypted data
• Monitor and audit all access to data encrypted by Jervis until the upgrade is completed